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Timing of children's vaccinations in 45 low-income and middle-income countries: an analysis of survey data
Abstract
Vaccinations are often delayed until well after the recommended ages, leaving many children exposed for longer than they should be. We estimated vaccination coverage at different ages, and delays in administration, in 45 low-income and middle-income countries.
We used data for 217 706 children from Demographic and Health Surveys between 1996 and 2005 (median 2002), which provided data for vaccination of children on the basis of events recorded on vaccination cards and interviews with mothers, with imputation of missing values and survival analysis. We devised an index combining coverage and delay.
For vaccinated children, the median of the median delays in the 45 countries was 2.3 weeks (IQR 1.4-4.6) for bacille Calmette-Guérin (BCG); 2.4 weeks (1.2-3.3) for diphtheria, tetanus, and pertussis (DTP1); 2.7 weeks (1.7-3.1) for measles-containing vaccine (MCV1); and 6.2 weeks (3.5-8.5) for DTP3. However, in the 12 countries with the longest delays for each vaccination, at least 25% of the children vaccinated were more than 10 weeks late for BCG, 8 weeks for DTP1, 11 weeks for MCV1, and 19 weeks for DTP3. Variation within countries was substantial: the median of the IQRs in the 45 countries for delay in DTP3 was 10.9 weeks, 7.9 weeks for MCV1, 5.4 weeks for BCG, and 5.3 weeks for DTP1. The median of the national coverage rates for DTP1 increased from 57% in children aged 12 weeks to 88% at 12 months, and for DTP3 from 65% at 12 months to 76% at 3 years.
The timeliness of children's vaccination varies widely between and particularly within countries, and published yearly estimates of national coverage do not capture these variations. Delayed vaccination could have important implications for the effect of new and established vaccines on the burden of disease.
WHO's Initiative for Vaccine Research.
... Comprehensive analyses of vaccination timeliness across multiple countries have already been performed [9,10] using Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) data. However, these analyses are relatively old (they were published in 2009 and 2011, respectively), and only included timeliness of vaccination against tuberculosis (Bacillus Calmette-Guérin, BCG), Diphtheria-Tetanus-Pertussis (DTP), polio or with a Measles-Containing Vaccine (MCV). ...
... Furthermore, most assessments categorise vaccination timing using "early vaccination", "timely vaccination" / "not delayed" and "delayed vaccination" grouping [8, 11-13, 19, 20], which does not analyse delay as a continuous variable and thus does not quantify how large or small delays are. Few studies analyse vaccination timing as a continuous variable [9,10,14,21], which facilitates comparison between different research studies, while using "delayed" / "not delayed" categorisation could be biased by different definitions across analyses. ...
... Median vaccination delay was lowest for birth doses: BCG (1 week (IQR: 0 to 4)), HepB-BD (0 (0 to 0)) and OPV-BD (0 (0, 2)) (Fig 2, S6 Table). The later the dose in the vaccine course, the larger the delay observed; for example, median delay was 1 (0, 4) weeks for DTP-1 versus 4 (2,9) weeks for DTP-3, and 1 (0, 4) for OPV-1 versus 4 (2, 9) for OPV-3 (Fig 2, S6 Table). Furthermore, later doses in vaccine courses also presented longer tails in the delay distribution Coverage per week of age is calculated as the cumulative proportion of children vaccinated at each week of age. ...
Vaccination timeliness is often not considered among standard performance indicators of routine vaccination programmes, such as vaccination coverage, yet quantifying vaccination delay could inform policies to promote in-time vaccination and help design vaccination schedules. Here, we analysed vaccination timeliness for 24 routine childhood immunisations for 54 countries. We extracted individual vaccination status and timing from Demographic and Health Surveys data from 54 countries with surveys from 2010 onwards. Individual data was used to estimate age at vaccination for <5 year-old children. Recommended age of vaccination for each country and vaccine was compared to the age at vaccination to determine vaccination delay. The evolution of vaccination delay over time was described using estimates from different birth cohorts. To identify socio-demographic indicators associated with delayed vaccination, we used multivariable Cox regression models with country as random effect and estimated the Hazard Ratio for vaccination with each vaccine-dose for each week post recommended vaccination age. Vaccine coverage at the recommended age was highest for birth and first doses (e.g. 50.5% BCG, 18.5% DTP-D1) and lowest for later doses (e.g. 5.5% DTP-D3, 16.3% MCV-D1, 8.2% MCV-D2). Median delay was lowest for birth doses, e.g. BCG (1 week (IQR: 0 to 4)), and it increased with later doses in vaccination courses: 1 (0, 4) week for DTP-D1 versus 4 (2, 9) weeks for DTP-D3. Although the median delay for each vaccine-dose remained largely constant over time, the range of delay estimates moderately decreased. Children living in rural areas, their countries’ poorer wealth quintiles and whose mothers had no formal education were more likely to received delayed vaccinations. Although we report most children are vaccinated within the recommended age window, we found little reduction on routine immunisation delays over the last decade and that children from deprived socioeconomic backgrounds are more likely to receive delayed vaccinations.
... Delayed vaccination was the most common dimension of untimely vaccination, with the highest proportion and longest median number of days children were vaccinated outside the recommended time-frames. Our findings do not align with prior research on vaccination timeliness, as the proportion of delayed vaccinations and the median delays in our study are generally lower compared to the largest study so far that included data of 217,706 children from 45 LMICs [35]. Our findings demonstrate that the Gambia EPI not only achieves high routine childhood vaccination coverage rates but has also ensured that children receive their vaccinations within the recommended time-frames, as much as possible, in comparison to other LMICs. ...
... For the multi-series vaccines, the proportion and median delays increased gradually and peaked with the third doses, reflecting a pattern similar to previous studies from Indonesia [37], the UK [38], and across LMICs context [35]. This trend is not surprising because the first doses of the multi-series vaccines are administered at two months of life in The Gambia which coincides with the first vaccination visit outside the birth period and may also be an opportunity to receive post-natal services, hence, the timely uptake. ...
... To conduct timeliness analysis in situations where dates of birth and vaccination are incomplete, there is a need to develop, validate, and deploy methodologies that can input or predict age at vaccination especially in situations where it can be confirmed from maternal recall that the child has been vaccinated. Such imputation or prediction techniques can utilize machine learning approaches that may leverage pre-specified characteristics such as the age at vaccination of children in similar age bands or living in the same spatial location with the index child [35,46]. ...
The Gambia’s routine childhood vaccination programme is highly successful, however, many vaccinations are delayed, with potential implications for disease outbreaks. We adopted a multi-dimensional approach to determine the timeliness of vaccination (i.e., timely, early, delayed, and untimely interval vaccination). We utilised data for 3,248 children from The Gambia 2019–2020 Demographic and Health Survey. Nine tracer vaccines administered at birth and at two, three, four, and nine months of life were included. Timeliness was defined according to the recommended national vaccination windows and reported as both categorical and continuous variables. Routine coverage was high (above 90%), but also a high rate of untimely vaccination. First-dose pentavalent vaccine (PENTA1) and oral polio vaccine (OPV1) had the highest timely coverage that ranged from 71.8% (95% CI = 68.7–74.8%) to 74.4% (95% CI = 71.7–77.1%). Delayed vaccination was the commonest dimension of untimely vaccination and ranged from 17.5% (95% CI = 14.5–20.4%) to 91.1% (95% CI = 88.9–93.4%), with median delays ranging from 11 days (IQR = 5, 19.5 days) to 28 days (IQR = 11, 57 days) across all vaccines. The birth-dose of Hepatitis B vaccine had the highest delay and this was more common in the 24–35 months age group (91.1% [95% CI = 88.9–93.4%], median delays = 17 days [IQR = 10, 28 days]) compared to the 12–23 months age-group (84.9% [95% CI = 81.9–87.9%], median delays = 16 days [IQR = 9, 26 days]). Early vaccination was the least common and ranged from 4.9% (95% CI = 3.2–6.7%) to 10.7% (95% CI = 8.3–13.1%) for all vaccines. The Gambia’s childhood immunization system requires urgent implementation of effective strategies to reduce untimely vaccination in order to optimize its quality, even though it already has impressive coverage rates.
... . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Peak IS481 Ct Unique subjects [45,43] ( ...
... Pertussis remains a leading vaccine-preventable disease that is endemic worldwide, and whose global impacts have been underscored by its dramatic post-pandemic resurgence across a range of countries (40,41,42,43,1). This is despite generally high national vaccine coverage (44,1), though considerable variation in vaccine uptake and timing exists worldwide (45,46,47,35,1). Further complicating this picture are major gaps in pertussis surveillance at the national and subnational level, particularly in LMICs, as well as rapidly shifting diagnostic methods and standards (48,49,50). ...
Pertussis remains an enigma partly due to the uncertain impact of asymptomatic cases on transmission. Contributing to this knowledge gap is a lack of high-quality disease surveillance, particularly in those low- and middle-income countries that experience high disease burdens. Here we present analyses based on our prospective longitudinal surveillance of a rolling cohort of 1,315 mothers and their newborn infants in Lusaka, Zambia across 2015 (8,704 unique study visits). We detail the timing, duration, and intensity of qPCR-based IS481 signals in individual subjects and within mother/infant dyads. We find that IS481 signal strength: A) in mothers predicts contemporaneous and future IS481 detections in infants, B) in infants predicts, to a lesser extent, detections in mothers, and C) predicts respiratory symptoms in infants but not mothers. We profile a subgroup of 50 infants and 54 mothers who displayed evidence of persistent colonization (median duration 8 weeks) wherein most mothers were entirely asymptomatic. We also include a critical assessment of qPCR test reliability across IS481 signal strengths. Our results indicate that pertussis transmission routinely occurs between minimally symptomatic mothers and their newborn infants, and demonstrate the routine occurrence of long-duration, mild and minimally symptomatic pertussis infections.
... Timely vaccination at birth is reported to have the most beneficial effects on reducing TB-related death in children compared to a later schedule, eg, six weeks after birth or at the recommended age of the first dose of diphtheria, tetanus, and pertussis (DTP) vaccination [3]. In fact, delayed BCG vaccination is commonly reported in low-middle income countries (LMICs), where administration may be delayed by up to 10 weeks [4]. ...
... Despite this high vaccination coverage, Indonesia's TB incidence remains the third-highest globally [7]. This can be partly explained by the substantially lower vaccination coverage among within first two months of life, at almost half compared to the national coverage [4,8,9]. Furthermore, coverage differs between regions, from 69.8% in Papua to 98.9% in Yogyakarta [6]. ...
Background:
Bacillus Calmette-Guérin (BCG) vaccination is recommended at birth or in the first week of life to achieve the most beneficial effects in protecting against the most severe type of tuberculosis (TB) disease in children. However, delayed vaccination is commonly reported, especially in outreach or rural areas. We assessed the cost-effectiveness of combining non-restrictive open vial and home visit vaccination strategies in order to increase timely BCG vaccination in a high-incidence outreach setting.
Methods:
We applied a simplified Markov model for the Papua setting, which resembled a high-incidence outreach setting in Indonesia, to assess the cost-effectiveness of these strategies from a health care and a societal perspective. A moderate increase (75% wastage rate and 25% home vaccination) and a large increase (95% wastage rate and 75% home vaccination) scenario were assessed in the analysis. We calculated incremental cost-effectiveness ratios (ICER) based on the incremental costs and quality-adjusted life years (QALYs) gained by comparing the two strategies to the base case scenario (35% wastage rate and no home vaccination).
Results:
The costs per vaccinated child were US10.54) and large increase scenarios (US288/QALY and US$487/QALY, respectively, for the moderate and large increase scenarios. Using Indonesia's gross domestic product (GDP) per person as a threshold, both strategies were considered to be cost-effective.
Conclusions:
We found that the allocation of resources for timely BCG vaccination based on combining home vaccination and a less restrictive open vial strategy could substantially reduce childhood TB cases and TB-related mortality. Although outreach activities are more expensive than vaccination at a health care facility only, these activities proved to be cost-effective. These strategies might also be beneficial in other high-incidence outreach settings.
... In our study, workers who worked in government hospitals and non-Bahraini workers had significantly higher vaccine hesitancy compared to the others. Many factors were reported to be associated with vaccine hesitancy, but there was no universal algorithm; the independent and relative strength of influence of each factor is complex and context-specific, varying across time, place, and type of vaccine [25,26]. Vaccine hesitancy was linked during the SARS-CoV-2 pandemic to a fear of vaccine-related adverse side effects in many published studies [27][28][29][30]. ...
... 1. Insight into mechanisms: Insight into the molecular mechanisms that allow BCG to enhance "early clearance" would directly support the design of future TB vaccines based on the fundamental properties of systemic dissemination, that is, the ability to induce memory in both adaptive and innate immune compartments [1,21] Given that epithelial skin barriers change rapidly early in life, any delay in administering BCG immediately at birth, even by a few days, may reduce propensity for systemic spread and with that the protective benefit [20]. While the World Health Organization currently recommends that BCG be given at birth, <50% of newborns in the world receive BCG prior to the end of their first month of life [24]. The reasons for this delay are multifactorial yet include restrictive vial-opening policies that could readily be changed [25]. ...
Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) and is the leading cause of death. Bacillus Calmette–Guérin (BCG) is the only licensed TB vaccine. Preclinical studies have shown that in adults intravenous administration of BCG improves protection against TB. We hypothesize that intradermal administration of BCG to the human newborn leads to low grade BCG bacteraemia and that this systemic dissemination improves protection against Mtb infection. This hypothesis is based on supporting observations including animal and human studies. It is a testable hypothesis and offers to deliver immediately actionable insight to advance the global efforts against TB.
... 8 And also, postponing immunizations raises a person's risk of contracting a potentially fatal VPD. 9 These will lead to lower community-level herd immunity and intervention success rates, 10 full vaccination series completion rates, 11 and elevated risk of infectious illnesses under control. 12 Globally, immunization is one of the maximum cost-effective techniques in growing infant survival, saving 2 to 3 million infant deaths every year from vaccine-preventable illnesses (VPDs). 13 A vaccine can also additionally have avoided one disorder out of each twenty that claimed an infant's life in 2019. ...
Plain Language Summary
Vaccine-preventable diseases are a serious problem that contributes to the death rate of children in developing countries such as Ethiopia. Some studies have shown that these VPDs are one of the factors affecting children’s health. Vaccination at the appropriate time is one of the key methods for promoting children’s health by improving the level of body immunity. Various studies have been conducted on the full coverage of vaccination in Ethiopia, but there are limited data on timing of vaccination and its predisposing factors in Wolaita Zone Public hospitals, southern Ethiopia. Participants were accessed through systematic sampling methods. The data were collected through administering structured questionnaires, and the Epi data V4.6 and SPPSS V.25 were used to enter and analyze, respectively.
In this study, we estimate the prevalence and factors associated with the vaccination timeliness in children between the ages of 0 and 23 months in the study area. The results showed that 71.5% of children were vaccinated on time. Possible factors identified for timely vaccination are the time to reach the health facility, the birthplace, and the follow-up of the ANC, the attitude of women and knowledge of the vaccine period. In summary, vaccination time is a gap in the field of research. Consequently, it is necessary to improve vaccines in time and to identify factors. This in turn promotes the health of children.
... Moreover, the study found that rural parents were less likely to demonstrate good practices, as also observed in research from other developing regions where geographic barriers hinder healthcare access 25,26 . To bridge these gaps, outreach programs, mobile immunization units, and community health workers could be instrumental in delivering vaccines and educating parents in hard-to-reach areas 27 . Policy Implications and Recommendations: To improve immunization coverage, targeted interventions addressing the identified gaps in knowledge, attitudes, and practices are essential. ...
Introduction: Childhood immunization is one of the most cost-effective public health interventions to prevent vaccine-preventable diseases and improve child survival. In Nepal, the national immunization program aims to ensure that all children receive the recommended vaccines, yet challenges remain in achieving universal coverage. The Knowledge, Attitude, and Practice (KAP) of parents towards immunization play a critical role in vaccine uptake. This study was designed to assess their understanding, attitudes, and behaviors toward vaccinating their children.
Methods: A prospective observational cross-sectional study was conducted from April 22, 2023, to October 2023 GP Koirala National Centre for Respiratory Diseases and Hospital, Tanahun, Gandaki Nepal, involving 227 parents of children under 18 months. The participants were selected through purposive sampling from Pediatric OPD of this hospital.A structured questionnaire was used to collect data about their knowledge, attitude, and practices regarding childhood immunization. The data were analyzed using SPSS version 23 with descriptive statistics, with results expressed as frequencies and percentages and Chi-square tests employed to identify associations between demographic variables and KAP levels.
Results: The study revealed that 73.6% of parents had good knowledge about childhood immunization, recognizing the importance of vaccines and being aware of the vaccination schedule. However, only 64.3% of parents demonstrated a favorable attitude toward immunization, reflecting mixed perceptions about the necessity of vaccines and their safety. Additionally, 60.3% of parents exhibited good practices, indicating that while a majority ensured their children received vaccines, there were still gaps in adherence to the full immunization schedule. Demographic factor such as education level significantly influenced KAP scores.
Conclusion: The study highlights the need for continuous efforts to enhance parental knowledge, improve attitudes, and reinforce good practices regarding childhood immunization in Nepal. Although the majority of parents showed a reasonable understanding of vaccines, the discrepancies in attitudes and practices suggest that targeted interventions, including education and outreach, are necessary to improve vaccination rates. Addressing these gaps is crucial to ensuring complete immunization coverage and safeguarding children from preventable diseases.
Keywords: Childhood immunization, parental knowledge, vaccination practices, public health, vaccine uptake.
... [32] We included real-world vaccine delays and vaccine timeliness (coverage by week of age) using an analysis of data from a recent nationally representative survey, MICS 2022. [25,33] (Table 1) We used estimates from a recent test-negative case-control study to approximate VE by time since dose administration using follow-up durations of 8 and 16 months for dose 1, and 7 and 15 months for dose 2. [12] We tted a parametric gamma curve to each dose, assuming VE would be very high shortly after dose administration and then fall to very low levels after around 18 months of follow-up. ( Figure S2) Estimates of VE and waning were very similar for doses 1 and 2, so we assumed the same waning rate for both. ...
Introduction
Afghanistan added ROTARIX to the routine national immunization programme in 2018. We aimed to estimate the cost-effectiveness and benefit-risk of ROTARIX and compare its continued use with other rotavirus vaccines that could be used in the future.
Methods
We used a static cohort model with a finely disaggregated age structure (weeks of age < 5 years) to assess the use of ROTARIX (1-dose vial) over a seven-year period (2018–2024) in Afghanistan. The primary outcome measure was the discounted cost (2022 US 4.4 million per year. The cost per DALY averted was US 471 (0.94 times the national GDP per capita) when incorporating the full vaccine price without Gavi's subsidy and excluding household costs averted by vaccination. When assuming continued Gavi support over the period 2025–2034, the dominant product would be ROTARIX. Without Gavi support, ROTASIIL (2-dose vial) dominates.
Conclusion
Our study supports the sustained use of rotavirus vaccination in Afghanistan. The rotavirus vaccine is cost-effective and is health benefits greatly exceed its potential health risks.
... This study makes an important contribution to the limited understanding of vaccination timeliness in Ghana, since previous studies had a limited geographic scope, focused solely on infant vaccines, and were conducted prior to the establishment of the 2YL platform [16][17][18][19]. Although previous research suggested that delays in infant vaccinations were common in Ghana, similar to other low-and middle-income countries (LMIC), the extent of subnational variation in vaccination timeliness remains to be explored [20]. ...
Strengthening routine immunization systems to successfully deliver childhood vaccines during the second year of life (2YL) is critical for vaccine-preventable disease control. In Ghana, the 18-month visit provides opportunities to deliver the second dose of the measles–rubella vaccine (MR2) and for healthcare workers to assess for and provide children with any missed vaccine doses. In 2016, the Ghana Health Service (GHS) revised its national immunization policies to include guidelines for catch-up vaccinations. This study assessed the change in the timely receipt of vaccinations per Ghana’s Expanded Program on Immunizations (EPI) schedule, an important indicator of service quality, following the introduction of the catch-up policy and implementation of a multifaceted intervention package. Vaccination coverage was assessed from household surveys conducted in the Greater Accra, Northern, and Volta regions for 392 and 931 children aged 24–35 months with documented immunization history in 2016 and 2020, respectively. Age at receipt of childhood vaccines was compared to the recommended age, as per the EPI schedule. Cumulative days under-vaccinated during the first 24 months of life for each recommended dose were assessed. Multivariable Cox regression was used to assess the associations between child and caregiver characteristics and time to MR2 vaccination. From 2016 to 2020, the proportion of children receiving all recommended doses on schedule generally improved, the duration of under-vaccination was shortened for most doses, and higher coverage rates were achieved at earlier ages for the MR series. More timely infant doses and caregiver awareness of the 2YL visit were positively associated with MR2 vaccination. Fostering a well-supported cadre of vaccinators, building community demand for 2YL vaccination, sustaining service utilization through strengthened defaulter tracking and caregiver-reminder systems, and creating a favorable policy environment that promotes vaccination over the life course are critical to improving the timeliness of childhood vaccinations.
... Despite medical advancements, VPDs still affect children owing to variation in immunization rates (Victora et al., 2003;World Health Organization, 2002). It was highlighted that vaccine refusal or delay may lead to disparities in vaccine coverage and uptake, which are vital factors in controlling VPDs (Clark & Sanderson, 2009). ...
This paper explores the spatial variation and determinants of child immunization coverage across districts in India by using the data of National Family Health Survey- 5. Previous studies have not adequately addressed regional differences in vaccination rates and underlying factors at the district level. The present study aims to fill this gap using sophisticated geostatistical techniques, with a special focus on full immunization, Bacillus Calmette Guerin, diphtheria-pertussis-tetanus, polio, and measles vaccines. The spatial distribution of immunization coverage across districts is analyzed, with three coverage categories: low, medium, and high. Economically disadvantaged states like Assam, Bihar, and Uttar Pradesh, as well as relatively affluent states, show varied coverage rates. This study examines the impact of the multiple determinants on immunization coverage, encompassing factors such as maternal and child health services, out-of-pocket expenditure, maternal education, and rates of institutional birth. Spatial autocorrelation is assessed using univariate Moran’s I, identifying clusters of high and low coverage. The study uses spatial regression models, spatial lag and spatial error, to account for spatial dependencies in the data. Significant factors positively associated with vaccination coverage include breastfeeding children with adequate diets, mother and child protection cards, maternal antenatal care, neonatal tetanus and postnatal care. However, out-of-pocket expenditure, health insurance, and women’s education exhibit limited impact on coverage. The findings of the current study emphasize the spatially dependent nature of childhood immunization coverage, revealing crucial determinants that influence regional variation and could guide targeted interventions for improved vaccination rates.
... Age-appropriate vaccines have, thus, been identified as an essential health intervention for child protection against mortality and morbidity, which has been closely looked at in many countries in recent years (8)(9)(10)(11)(12). The design of its schedule is based on when the immune system can safely respond to the vaccine and age-related diseases that can impact child morbidity and mortality, through which it can reduce the risk of infection of VPDs among infants and children in early life (13). ...
Introduction
Routine immunization programs have focused on increasing vaccination coverage, which is equally important for decreasing vaccine-preventable diseases (VPDs), particularly in low- and lower-middle-income countries (LMICs). We estimated the trends and projections of age-appropriate vaccination coverage at the regional and national levels, as well as place of residence and wealth index in LMICs.
Methods
In total, 174 nationally representative household surveys from 2000 to 2020 from 41 LMICs were included in this study. Bayesian hierarchical regression models were used to estimate trends and projections of age-appropriate vaccination.
Results
The trend in coverage of age-appropriate Bacillus Calmette-Guérin (BCG), third dose of diphtheria, tetanus, and pertussis (DTP3), third dose of polio (polio3), and measles-containing vaccine (MCV) increased rapidly from 2000 to 2020 in LMICs. Findings indicate substantial increases at the regional and national levels, and by area of residence and socioeconomic status between 2000 and 2030. The largest rise was observed in East Africa, followed by South and Southeast Asia. However, out of the 41 countries, only 10 countries are estimated to achieve 90% coverage of the BCG vaccine by 2030, five of DTP3, three of polio3, and none of MCV. Additionally, by 2030, wider pro-urban and -rich inequalities are expected in several African countries.
Conclusion
Significant progress in age-appropriate vaccination coverage has been made in LMICs from 2000 to 2020. Despite this, projections show many countries will not meet the 2030 coverage goals, with persistent urban–rural and socioeconomic disparities. Therefore, LMICs must prioritize underperforming areas and reduce inequalities through stronger health systems and increased community engagement to ensure high coverage and equitable vaccine access.
... Ad also, postponing immunizations raises a person's risk of contracting a potentially fatal VPD [9]. These will lead to lower community-level herd immunity and intervention success rates [10], full vaccination series completion rates [11], and elevated risk of infectious illnesses under control [12]. ...
Background
In Ethiopia, vaccination is mentioned as the vital preventive measure of undue childhood mortality from measles, pneumonia, diarrheal diseases, and other VPDs. Although there are studies conducted on full vaccine coverage, there is relatively no data available about timely vaccination and its related factors in southern Ethiopia. Thus, this study assessed timely vaccination and related factors in children who age from 0 to 23 months in the study area.
Methods and material
An institution-based cross-sectional study was undertaken in Wolaita zone Public hospitals, from December 2023, G.C to January 2024, G.C. A total of 376 study subjects were randomly selected through systematic sampling method among parents with children who are 0–23 months old. Data were gathered by questionnaire with a structure which was based on mother’s recalling as well as vaccination cards. A basic questionnaire was completed by respondents and the responses were entered into Epidata Version 4.6, which was later transferred to SPSS Version 23 for analysis. Data were entered into Epidata Version 4.6 and exported to SPSS Version 23 for analysis. An adjusted odds ratio (AOR) along with a 95% confidence interval at a P-value less than 0.05 was used to declare significance level.
Results
A total of 376 study participants responded to the interview with 100% response rate. This study found that 269 children (71.5%) were timely vaccinated and 107 children (28.5%) had not got their children vaccinated timely. The independent variables, like time to reach the health facility[AOR = 5.7; 95% CI (1.81,17.55), place of delivery[AOR = 4.91; 95% CI (2.85, 10.83)], ANC follow-up[AOR = 8; 95% CI (5.81, 25.01)], attitude[AOR = 2.5; 95% CI (1.23,4.3)] and knowledge [AOR = 3.45; 95% CI (1.61, 10.62)] on the vaccine time, significantly attributed to timely vaccination.
Conclusion
71.5% of study participants vaccinated their children on the national recommended vaccination schedule. The research also revealed statistical correlation between time taken from home to health facility, antenatal care follow up, place of delivery, maternal attitude and knowledge of the prompt vaccination and vaccination timeline. For the all stake holders, highly strategic interventions like promoting maternal knowledge about the benefits versus risks of timely vaccination, community-based vaccination programs or campaigns, routine supervision, and counseling during antenatal visits are very effective ways of improving timely vaccination.
... Global health indicators such as blood pressure, weight, and height are critical for monitoring both national and international health system performance. Such markers are largely collected through household surveys, which are often seen as the gold standard methodology due to their population-representative nature (1)(2)(3)(4)(5). ...
Health agencies rely upon survey-based physical measures to estimate the prevalence of key global health indicators such as hypertension. Such measures are usually collected by non-healthcare worker personnel and are potentially subject to measurement error due to variations in interviewer technique and setting, termed “interviewer effects”. In the context of physical measurements, particularly in low- and middle-income countries, interviewer-induced biases have not yet been examined. Using blood pressure as a case study, we aimed to determine the relative contribution of interviewer effects on the total variance of blood pressure measurements in three large nationally-representative health surveys from the Global South. We utilized 169,681 observations between 2008 and 2019 from three health surveys (Indonesia Family Life Survey, National Income Dynamics Study of South Africa, and Longitudinal Aging Study in India). In a linear mixed model, we modeled systolic blood pressure as a continuous dependent variable and interviewer effects as random effects alongside individual factors as covariates. To quantify the interviewer effect-induced uncertainty in hypertension prevalence, we utilized a bootstrap approach comparing sub-samples of observed blood pressure measurements to their adjusted counterparts. Our analysis revealed that the proportion of variation contributed by interviewers to blood pressure measurements was statistically significant but small: approximately 0.24-2.2% depending on the cohort. Thus, hypertension prevalence estimates were not substantially impacted at national scales. However, individual extreme interviewers could account for measurement divergences as high as 12%. Thus, highly biased interviewers could have important impacts on hypertension estimates at the sub-district level.
... Consistent with prior literature on childhood immunization, older children across all regions were more likely to be vaccinated with either dose compared to younger children. Although older children have a comparatively longer window of opportunity to receive the vaccine, it is also possible that the finding could reflect delays in vaccination, as studies from other low-and middle-income countries have suggested [30,31]. Further research on the timing or age of 2YL vaccine receipt could provide a better understanding of the latter hypothesis. ...
Background:
Understanding the drivers of coverage for vaccines offered in the second year of life (2YL) is a critical focus area for Ghana's life course approach to vaccination. This study characterizes the predictors of vaccine receipt for 2YL vaccines-meningococcal serogroup A conjugate vaccine (MACV) and the second dose of measles-containing vaccine (MCV2)-in Ghana.
Methods:
1522 children aged 18-35 months were randomly sampled through household surveys in the Greater Accra Region (GAR), Northern Region (NR), and Volta Region (VR). The association between predictors and vaccination status was modeled using logistic regression with backwards elimination procedures. Predictors included child, caregiver, and household characteristics.
Results:
Coverage was high for infant vaccines (>85%) but lower for 2YL vaccines (ranging from 60.2% for MACV in GAR to 82.8% for MCV2 in VR). Predictors of vaccination status varied by region. Generally, older, first-born children, those living in rural settlements and those who received their recommended infant vaccines by their first birthday were the most likely to have received 2YL vaccines. Uptake was higher among those with older mothers and children whose caregivers were aware of the vaccination schedule.
Conclusions:
Improving infant immunization uptake through increased community awareness and targeted strategies, such as parental reminders about vaccination visits, may improve 2YL vaccination coverage.
... Schedules which begin later and have longer intervals between doses are more immunogenic [11][12][13]. In reality, delivery of the EPI schedule on time is challenging for many countries; of 45 studied countries, the median delay for DTP1 was 2.4 weeks, and the median delay for DTP3 was 6.2 weeks [14]. ...
Background
Universal immunisation is the cornerstone of preventive medicine for children, The World Health Organisation (WHO) recommends diphtheria-tetanus-pertussis (DTP) vaccine administered at 6, 10 and 14 weeks of age as part of routine immunisation. However, globally, more than 17 unique DTP-containing vaccine schedules are in use. New vaccines for other diseases continue to be introduced into the infant immunisation schedule, resulting in an increasingly crowded schedule. The OptImms trial will assess whether antibody titres against pertussis and other antigens in childhood can be maintained whilst adjusting the current Expanded Programme on Immunisation (EPI) schedule to provide space for the introduction of new vaccines.
Methods
The OptImms studies are two randomised, five-arm, non-inferiority clinical trials in Nepal and Uganda. Infants aged 6 weeks will be randomised to one of five primary vaccination schedules based on age at first DTwP-vaccination (6 versus 8 weeks of age), number of doses in the DTwP priming series (two versus three), and spacing of priming series vaccinations (4 versus 8 weeks). Additionally, participants will be randomised to receive their DTwP booster at 9 or 12 months of age. A further sub-study will compare the co-administration of typhoid vaccine with other routine vaccines at one year of age. The primary outcome is anti-pertussis toxin IgG antibodies measured at the time of the booster dose. Secondary outcomes include antibodies against other vaccine antigens in the primary schedule and their safety.
Discussion
These data will provide key data to inform policy decisions on streamlining vaccination schedules in childhood.
Trial registrations
ISRCTN12240140 (Nepa1, 7th January 2021) and ISRCTN6036654 (Uganda, 17th February 2021).
... Many studies have reported immunization coverage in Nigeria, but few have given attention to timeliness of vaccines. A recent systematic review on timeliness of vaccination identified four studies from Nigeria with relevant data [15] and the four studies were conducted in urban areas [16][17][18][19]. Sadoh and colleagues [16] examined the hospital records of a government owned immunization clinic in Benin, and reported that the timeliness for each of the vaccines ranged from 18.7% to 61.5% and delays occurred in 18.9% and 65.0% for different vaccines. ...
Background
Suboptimal infant vaccination is common in Nigeria and multiple interventions have been deployed to address the situation. Child health indicators are reported to be worse in urban slums compared with other urban areas, but urban data are usually not disaggregated to show these disparities. Examining the timeliness and completion of infant vaccination in urban slums is important to determine the effectiveness of existing interventions in improving infant vaccination among this vulnerable population. This study explored the trends of infant vaccination in selected urban slum communities in Ibadan, Southwest Nigeria between November 2014 and October 2018.
Methods
This was a cross sectional study where infant vaccination data were extracted from the immunization clinic records of six primary health care centers that were providing infant vaccination services for seven urban slum communities. Data was analyzed using descriptive statistics and Chi square test at α = 05.
Results
A total of 5,934 infants vaccination records were reviewed, 2,895 (48.8%) were for female infants and 3,002(50.6%) were from Muslim families. Overall, only 0.6% infants had both timely and complete vaccination during the four years under study. The highest number of infants with timely and complete vaccination were seen in 2015(12.2%) and least in 2018(2.9%). Regarding timeliness of the vaccines, BCG, was the least timely among the vaccines given at birth and the pentavalent and oral polio vaccines’ timeliness reduced as the age of the infants increased. Both yellow fever and measles vaccines were timelier than the pentavalent vaccines. Vaccines were most timely in 2016(31.3%) and least timely in 2018(12.1%). Those from Muslim families significantly had delayed and incomplete vaccinations compared with those from Chrisitan families (p = 0.026).
Conclusion
Infant vaccinations were significantly delayed and incomplete in the study communities during the years reviewed. More focused interventions are required to ensure optimal vaccination of the infants.
... Despite a significant drops in the prevalence of vaccinepreventable deaths, a significant portion of children are not fully vaccinated, which results in substantial regional and international variation in vaccination coverage. 15,16 For example, in 2017, ~83K measles-related fatalities were tabulated worldwide out of an estimated 17 million cases. 17,18 Worldwide~116 million newborns (86%) received full 3 doses of the diphtheria-tetanus-pertussis (DTP) vaccine in 2018. ...
Immunization is one of the most cost-effective measures to prevent morbidity and mortality in children. Therefore, the purpose of this systematic review and meta-analysis was to determine the pooled prevalence of incomplete immunization among children in Africa as well as its determinants. PubMed, Google Scholar, Scopus, Science Direct, and online institutional repository homes were searched. Studies published within English language, with full text available for searching, and studies conducted in Africa were included in this meta-analysis. A pooled prevalence, Sub-group analysis, sensitivity analysis and meta-regression were conducted. Out of 1305 studies assessed, 26 met our criteria and were included in this study. The pooled prevalence of incomplete immunization was 35.5% (95% CI: 24.4, 42.7), I² = 92.1%). Home birth (AOR=2.7; 95% CI: 1.5–4.9), rural residence (AOR = 4.6; 95% CI: 1.1–20.1), lack of antenatal care visit (AOR = 2.6; 95% CI: 1.4–5.1), lack of knowledge of immunizations (AOR=2.4; 95% CI: 1.3–4.6), and maternal illiteracy (AOR = 1.7: 95%CI: 1.3–2.0) were associated with incomplete immunization. In Africa, the prevalence of incomplete immunization is high. It is important to promote urban residency, knowledge of immunization and antenatal follow up care.
... Despite medical and technological advancement, children suffer from vaccine-preventable diseases due to disparities in vaccine coverage [3,4]. In addition, delayed vaccination has a severe impact on the disease burden [5]. A previous study documented that refusing or delaying vaccination contributes to disparities in vaccine uptake and coverage, which are both essential to controlling vaccine-preventable diseases. ...
India’s Universal Immunization Programme has been performing at a sub-optimal level over the past decade, with there being a wide disparity in terms of immunization coverage between states. This study investigates the covariates that affect immunization rates and inequality in India at the individual and district levels. We used data from the five rounds of the National Family Health Survey (NFHS), conducted from 1992–1993 to 2019–2021. We used multilevel binary logistic regression analysis to examine the association between demographic, socio-economic and healthcare factors and a child’s full immunization status. Further, we used the Fairlie decomposition technique to understand the relative contribution of explanatory variables to a child’s full immunization status between districts with different immunization coverage levels. We found that 76% of children received full immunization in 2019–2021. Children from less wealthy families, urban backgrounds, Muslims, and those with illiterate mothers were found to have lower chances of receiving full immunization. There is no evidence that gender and caste disparities have an impact on immunization coverage in India. We found that having a child’s health card is the most significant contributor to reducing the disparities that exist regarding children’s full immunization between mid- and low-performing districts. Our study suggests that healthcare-related variables are more crucial than demographic and socio-economic variables when determining ways in which to improve immunization coverage in Indian districts.
... Current estimates of RSV disease age distribution have been derived from a relatively small number of disease incidence studies and have reported age distributions in wide age bands [1]. A systematic review of RSV age distributions could help to improve the precision of modelled impact estimates, particularly if paired with similarly granular data on the coverage and timeliness of RSV interventions [75]. Similar exercises have recently been conducted for rotavirus disease [76] and intussusception [12] and these methods (systematic review, parametric curve fitting) could be readily applied to RSV. ...
Background
Respiratory syncytial virus (RSV) is a leading cause of respiratory disease in young children. A number of mathematical models have been used to assess the cost-effectiveness of RSV prevention strategies, but these have not been designed for ease of use by multidisciplinary teams working in low-income and middle-income countries (LMICs).
Methods
We describe the UNIVAC decision-support model (a proportionate outcomes static cohort model) and its approach to exploring the potential cost-effectiveness of two RSV prevention strategies: a single-dose maternal vaccine and a single-dose long-lasting monoclonal antibody (mAb) for infants. We identified model input parameters for 133 LMICs using evidence from the literature and selected national datasets. We calculated the potential cost-effectiveness of each RSV prevention strategy (compared to nothing and to each other) over the lifetimes of all children born in the year 2025 and compared our results to a separate model published by PATH. We ran sensitivity and scenario analyses to identify the inputs with the largest influence on the cost-effectiveness results.
Results
Our illustrative results assuming base case input assumptions for maternal vaccination (3.50 per dose, 77% efficacy, 5 months protection) showed that both interventions were cost-saving compared to status quo in around one-third of 133 LMICs, and had a cost per DALY averted below 0.5 times the national GDP per capita in the remaining LMICs. UNIVAC generated similar results to a separate model published by PATH. Cost-effectiveness results were most sensitive to changes in the price, efficacy and duration of protection of each strategy, and the rate (and cost) of RSV hospital admissions.
Conclusions
Forthcoming RSV interventions (maternal vaccines and infant mAbs) are worth serious consideration in LMICs, but there is a good deal of uncertainty around several influential inputs, including intervention price, efficacy, and duration of protection. The UNIVAC decision-support model provides a framework for country teams to build consensus on data inputs, explore scenarios, and strengthen the local ownership and policy-relevance of results.
... Timely vaccination (also referred to as on-time vaccination or its reverse, delayed vaccination) is important to assess as delayed vaccination may lead to an increase in mortality and it increases the fraction of a population that requires vaccination in order to eliminate a disease [35,36]. When measured in other contexts, the proportion of children receiving timely vaccination has also often been low [37,38]. ...
Background
Cash transfer programmes are increasingly used in humanitarian contexts to help address people’s needs across multiple sectors. However, their impact on the key objectives of reducing malnutrition and excess mortality remains unclear. mHealth interventions show great promise in many areas of public health, but evidence for their impact on reducing the risk factors for malnutrition is uncertain. We therefore implemented a trial to determine the impacts of 2 interventions in a protracted humanitarian context, a cash transfer conditionality and mHealth audio messages.
Methods and findings
A 2 × 2 factorial cluster-randomised trial was implemented in camps for internally displaced people (IDP) near Mogadishu, Somalia, starting in January 2019. The main study outcomes were assessed at midline and endline and included coverage of measles vaccination and the pentavalent immunisation series, timely vaccination, caregiver’s health knowledge, and child diet diversity. Twenty-three clusters (camps) were randomised to receive or not receive conditional cash transfers (CCTs) and an mHealth intervention, and 1,430 households were followed up over 9 months. All camps received cash transfers made at emergency humanitarian level (US35). To be eligible to receive cash, households in camps receiving CCT were required to take their children <5 years age to attend a single health screening at a local clinic and were issued with a home-based child health record card. Participants in camps receiving the mHealth intervention were asked (but not required) to listen to a series of audio messages about health and nutrition that were broadcast to their mobile phone twice a week for 9 months. Participants and investigators were not blinded. Adherence to both interventions was monitored monthly and found to be high (>85%). We conducted intention-to-treat analysis.
During the humanitarian intervention phase, the CCT improved coverage of measles vaccination (MCV1) from 39.2% to 77.5% (aOR 11.7, 95% CI [5.2, 26.1]; p < 0.001) and completion of the pentavalent series from 44.2% to 77.5% (aOR 8.9, 95% CI [2.6, 29.8]; p = < 0.001). By the end of the safety net phase, coverage remained elevated from baseline at 82.2% and 86.8%, respectively (aOR 28.2, 95% CI [13.9, 57.0]; p < 0.001 and aOR 33.8, 95% CI [11.0, 103.4]; p < 0.001). However, adherence to timely vaccination did not improve. There was no change in the incidence of mortality, acute malnutrition, diarrhoea, or measles infection over the 9 months of follow-up.
Although there was no evidence that mHealth increased Mother’s knowledge score (aOR 1.32, 95% CI [0.25, 7.11]; p = 0.746) household dietary diversity increased from a mean of 7.0 to 9.4 (aOR 3.75, 95% CI [2.04, 6.88]; p < 0.001). However, this was not reflected by a significant increase in child diet diversity score, which changed from 3.19 to 3.63 (aOR 2.1, 95% CI [1.0, 4.6]; p = 0.05). The intervention did not improve measles vaccination, pentavalent series completion, or timely vaccination, and there was no change in the incidence of acute malnutrition, diarrhoea, measles infection, exclusive breastfeeding, or child mortality. No significant interactions between the interventions were found. Study limitations included the limited time available to develop and test the mHealth audio messages and the necessity to conduct multiple statistical tests due to the complexity of the study design.
Conclusions
A carefully designed conditionality can help achieve important public health benefits in humanitarian cash transfer programmes by substantially increasing the uptake of child vaccination services and, potentially, other life-saving interventions. While mHealth audio messages increased household diet diversity, they failed to achieve any reductions in child morbidity, malnutrition, or mortality.
Trial registration
ISRCTN ISRCTN24757827. Registered November 5, 2018.
... Our results highlighted that a part of the students did not consider the vaccination of health professionals as a prerequisite for working in the healthcare sector. It is known from the literature that there may be several factors associated with non-positive opinions among young people and that they are generally context-specific, and vary according to time, place, and vaccine type [28]. ...
(1) Background: Healthcare providers have a crucial role in contrasting vaccine hesitancy (VH). We aimed to investigate opinions, knowledge, and attitudes toward vaccines in healthcare students (HS) at the University of Catania (Italy). (2) Methods: A survey was conducted from 1 October 2019 to 31 January 2020. Data on the opinions, knowledge, and attitudes of HS toward vaccinations were collected using an anonymous self-administered questionnaire. The opinion answers were added to calculate the VH index (<18 = low, 19–22 = medium, >23 = high). Data were summarized by the VH index, degree, year of study, and sex differences, using descriptive statistics. (3) Results: A total of 1275 students (53.7% females) participated in the study, with a median (IQR) age of 21 (19–22) years. The median level of VH was 20 (17–23), with slightly higher values in males. We found an inverse trend between VH and opinions, knowledge, and attitudes toward vaccines. The same trend was confirmed in all study courses. Furthermore, the comparison between sexes revealed a higher level of knowledge in women. (4) Conclusions: The results highlight a lack of knowledge about vaccines, as well as contrasting opinions and attitudes among future health professionals. Therefore, future interventions on these topics in the preparation of future healthcare providers are needed.
... 10 A significant number of children are not fully vaccinated despite a huge decline in the occurrence of vaccine-preventable mortality, which causes a major regional and global variation in vaccination coverage. 11,12 For instance, out of more over 17 million cases of measles in the world in 2017, there were 83,439 fatalities. 13,14 In 2018, a full three doses of the diphtheria-tetanus-pertussis (DTP) vaccine were given to 116.3 million children worldwide (86%). ...
Immunization is cost-effective preventive strategy for child morbidity and mortality. PubMed, Google Scholar, Scopus, Science Direct, and online institutional repository homes were searched. Data were extracted by Microsoft excel. Begg’s rank test, and Egger’s regression test was done. A pooled prevalence, Sub-group analysis, sensitivity analysis and meta-regression were conducted. A total of 12 articles were included in this study. The pooled prevalence of vaccination dropout was 26.06% (95% CI: 11.59, 30.53), I2 =91.2%. In sub-group analysis, Nigeria had the highest prevalence of immunization dropouts (33.59%). It was 18.01% and 29.25%, respectively, for published and unpublished research. Community-based studies and institutional-based studies also yield a prevalence of dropout 39.04% and 13.73% respectively. Dropout rate was 22.66% for sample sizes under 500 and 18.01% for sample sizes beyond 500. In Sub-Saharan Africa, the prevalence of vaccination dropout was high. Community education about vaccinations importance should be prioritized.
... Several determinants of VH were identified by the studies included in this review. No single algorithm was applicable to all studies as each factor was independent and varied across time, place, and vaccines, reflecting the complex interplay of other variables and the context-specific nature of VH (Clark & Sanderson, 2009;Larson et al., 2015aLarson et al., , 2015b. Even in parts of the world where research was readily available, only few studies examined the different levels of interactions that exist between factors influencing VH. ...
Aim:
This review aims are to (1) identify relevant quantitative research on parental childhood vaccine hesitancy with vaccine uptake and vaccination intention being relevant outcomes and (2) map the gaps in knowledge on vaccine hesitancy to develop suggestions for further research and to guide interventions in this field.
Background:
Vaccine hesitancy recognises a continuum between vaccine acceptance and vaccine refusal, de-polarising past anti-vaccine, and pro-vaccine categorisations of individuals and groups. Vaccine hesitancy poses a serious challenge to international efforts to lessen the burden of vaccine-preventable diseases. Potential vaccination barriers must be identified to inform initiatives aimed at increasing vaccine awareness, acceptance, and uptake.
Methods:
Five databases were searched for peer-reviewed articles published between 1998 and 2020 in the fields of medicine, nursing, public health, biological sciences, and social sciences. Across these datasets, a comprehensive search technique was used to identify multiple variables of public trust, confidence, and hesitancy about vaccines. Using PRISMA guidelines, 34 papers were included so long as they focused on childhood immunisations, employed multivariate analysis, and were published during the time frame. Significant challenges to vaccine uptake or intention were identified in these studies. Barriers to vaccination for the target populations were grouped using conceptual frameworks based on the Protection Motivation Theory and the World Health Organization’s Strategic Advisory Group of Experts on Immunization Working Group model and explored using the 5C psychological antecedents of vaccination.
Findings:
Although several characteristics were shown to relate to vaccine hesitancy, they do not allow for a thorough classification or proof of their individual and comparative level of influence. Understudied themes were also discovered during the review. Lack of confidence, complacency, constraints, calculation, and collective responsibility have all been highlighted as barriers to vaccination uptake among parents to different degrees.
... (3) DPT1, PCV1, and polio1 from 4 weeks to 2 months; (4) DPT2, PCV2, and polio2 from 8 weeks to 4 months; (5) DPT3, PCV3, and polio3 from 12 weeks to 6 months; and (6) measles vaccine from 38 weeks to 12 months. 34 Measures of association were expressed as odds ratios (ORs). ...
Background:
Limited evidence exists regarding the drivers of vaccination coverage and equity in Kampala city, despite frequent measles outbreaks, inequities in vaccination coverage, and the decline in vaccination coverage rates. This study was designed to determine vaccine coverage among children aged 12-36 months and to understand its demand-side drivers.
Methods:
We utilized a mixed-methods parallel convergent study design. A household survey was conducted to quantify the drivers of vaccine coverage among households with children aged 12-36 months. We employed a multistage sampling approach to select households, using a primary sampling unit of an enumeration area. We conducted 30 key informant interviews, 7 focus group discussions, and 6 in-depth interviews with representatives from the immunization program, health workers, and parents residing in areas with low vaccine coverage.
Results:
Of the 590 enrolled children, 340 (57.6%) were partially vaccinated, 244 (41.4%) were fully vaccinated and had received all the recommended vaccinations, and 6 (1.0%) had never received any vaccine. Of the 244 with all recommended vaccinations, only 65 (26.6%) received their vaccines on time. Access to vaccination services was high (first dose of diphtheria, pertussis, and tetanus [DPT1] coverage of 96%), but utilization decreased over time, as shown by a dropout rate of 17.3% from the first to third dose of DPT. The main driver of complete vaccination was the parents' appreciation of the benefits of vaccination. Among partially vaccinated children, the barriers to vaccination were inadequate information about vaccination (its benefits and schedule), vaccine stock-outs, long waiting times to receive vaccination services, and hidden vaccination costs.
Conclusion:
Vaccination needs to be targeted to all children irrespective of whether they reside in slum areas or nonslum areas, as most are under-vaccinated. Social mobilization and communication efforts should be tailored to the complexities of urban settings characterized by transient and diverse populations with different cultures.
... As well, delays in vaccinations also increase the risk of infection with life-threatening VPDs at the individual level (9). These will be resulted in decreasing the intervention success and reducing herd immunity at the community level (10), in completing full vaccination series (11), and increasing the risk to the resurgence of infectious diseases that are under control (12). ...
Background
Globally, vaccination is one of the most cost-effective interventions in promoting child survival, preventing 2–3 million child deaths annually from vaccine-preventable diseases (VPDs). In Ethiopia, timely vaccination is stated as key to the prevention of unnecessary childhood mortality from measles, pneumonia, diarrheal diseases, and other VPDs. However, Ethiopia ranked fifth among the ten countries with the most unprotected children. Furthermore, previous vaccine timeliness studies produced widely disparate results. As a result, it was suggested that more research be conducted to investigate the potential factors behind the high proportion of untimely vaccination. Therefore, this study was intended to explore the association between different factors and the proportion of vaccination timeliness administered under the Expanded Program on Immunization in Debre Libanos district, Ethiopia.
Methods
A community-based cross-sectional study design was employed from 1 May to 30 May 2021 among children aged 12 to 23 months with their mother/caregiver, who had started vaccination and had vaccination cards in the Debre Libanos. Simple random sampling techniques and pretested semi-structured questionnaires were used for data collection. At last, a multivariable logistic regression was used to identify factors associated with the vaccination timeliness.
Result
In this study, 413 children aged 12 to 23 months were interviewed with their mother/caregiver. Overall, 33.7% [95% CI (29.1–38.3)] of children received their vaccines timely. Having a female child [AOR: 2.9, 95% CI: 1.58–5.35], mother/caregiver attending primary [AOR: 6.33, 95% CI: 2.66–15.06] and secondary/above education [AOR: 5.61, 95% CI: 2.41–13.04], sufficient vaccination knowledge [AOR: 3.46, 95% CI: 1.87–6.38], mother/caregiver with least hesitant [AOR: 3.35, 95% CI: 1.51–7.41] and middle hesitant [AOR: 1.89, 95% CI: 1.05–3.58], utilization of ANC [AOR: 2.89, 95% CI: 1.32–6.33], and giving birth at health facility [AOR: 4.32, 95% CI: 1.95–9.59] were the factors independently associated with vaccination timeliness.
Conclusion
In comparison to Ethiopia’s existing vaccination coverage, the proportion of children immunized at the recommended time interval is low in the study district. Policymakers should prioritize vaccine timeliness and integrate it into childhood vaccination strategies.
... The figure for delayed immunisation stood around 26% for both DPT 3 and OPV 3. Previous studies done in Sub-Saharan and low-middle-income countries also reported delays in age-appropriate immunisation despite high immunisation coverage. [18][19][20] Moreover, we found that delayed measles immunisation in India was associated with factors like place of residence, cultural affiliation, gender and birth order of the child, healthseeking behaviours and socioeconomic status. Consistent with the previous study, we observed that urban children were associated with delayed immunisation as than the children living in rural areas. ...
Background: Objectives were to identify the factors influencing the timeliness of measles immunisation in India, as well as to explore whether parental behaviour in health care seeking facilities varies depending on the gender of child.
Methods: A cross-sectional study was undertaken in India using secondary data from the fourth phase of the district level household and facility survey (DLHS 4). To estimate the age-specific coverage rates scientifically and thoroughly Kaplan-Meier survival analysis was applied. The risk factors for delayed measles immunisation were identified by using cox proportional hazard regression model.
Results: Individual factors, social factors, awareness, and facilitatory factors all have a significant impact on the timeliness of measles immunisation in India. Additionally, it can also be concluded that in the case of a male child, institutional delivery significantly improves health-seeking behaviour among the parents compared to a female child.
Conclusions: Numerous elements like the place of residence, economic position, and caste limit the timeliness of measles immunisation in India. Parents' health-seeking behaviour is also significant in the list of influential factors, like mother’s antenatal visit during pregnancy, the child's place of delivery, and motivation for child immunisation. In India child's gender and birth order discovered to have an impact on measles immunisation timeliness. Furthermore, we discovered that parents' health-seeking behaviour is not gender-neutral, but rather favours male child more.
... Delayed immunization is a strong risk factor for disease, because it leads to children having little to no immune protection via measles-containing vaccine (MCV) against measles infection after the waning of maternally acquired antibodies [4,5]. An analysis of the timing of measles vaccination in Uganda found that the median delay in the administration of MCV1 was 2.7 weeks, but with an interquartile range (IQR) of 9.6 weeks, indicating a wide distribution in the number of weeks MCV1 was delayed [6]. ...
Introduction
On-time measles vaccination is essential for preventing measles infection among children as early in life as possible, especially in areas where measles outbreaks occur frequently. Characterizing the timing of routine measles vaccination (MCV1) among children and identifying risk factors for delayed measles vaccination is important for addressing barriers to recommended childhood vaccination and increasing on-time MCV1 coverage. We aim to assess the timing of children's MCV1 vaccination and to investigate the association between demographic and healthcare factors, mothers'/caregivers' ability to identify information on their child’s vaccination card, and achieving on-time (vs. delayed) MCV1 vaccination.
Methods
We conducted a population-based, door-to-door survey in Kampala, Uganda, from June–August of 2019. We surveyed mothers/caregivers of children aged one to five years to determine how familiar they were with their child’s vaccination card and to determine their child’s MCV1 vaccination status and timing. We assessed the proportion of children vaccinated for MCV1 on-time and delayed, and we evaluated the association between mothers'/caregivers' ability to identify key pieces of information (child’s birth date, sex, and MCV1 date) on their child’s vaccination card and achieving on-time MCV1 vaccination.
Results
Of the 999 mothers/caregivers enrolled, the median age was 27 years (17–50), and median child age was 29 months (12–72). Information on vaccination status was available for 66.0% ( n = 659) of children. Of those who had documentation of MCV1 vaccination ( n = 475), less than half (46.5%; n = 221) achieved on-time MCV1 vaccination and 53.5% ( n = 254) were delayed. We found that only 47.9% ( n = 264) of the 551 mothers/caregivers who were asked to identify key pieces of information on their child's vaccination card were able to identify the information, but ability to identify the key pieces of information on the card was not independently associated with achieving on-time MCV1 vaccination.
Conclusion
Mothers'/caregivers' ability to identify key pieces of information on their child’s vaccination card was not associated with achieving on-time MCV1 vaccination. Further research can shed light on interventions that may prompt or remind mothers/caregivers of the time and age when their child is due for measles vaccine to increase the chance of the child receiving it at the recommended time.
... 34 The schedule is therefore DTP1, DTP2, and DTP3 accounting for potential country-specific delays based on DHS and MICS data. 35 The only exception is for oNGRV for which the study uses a neonatal schedule where the first dose is given at birth, accounting for earlier protection. Vaccine coverage proxies for oNGRV in the main scenario are therefore BCG, DTP1, and DTP2 and associated delays. ...
While current live, oral rotavirus vaccines (LORVs) are reducing severe diarrhea everywhere, their effectiveness is lower in high burden settings. Alternative approaches are in advanced stages of clinical development, including injectable next-generation rotavirus vaccine (iNGRV) candidates, which have the potential to better protect children, be combined with existing routine immunizations and be more affordable than current LORVs. In an effort to better understand the real public health value of iNGRVs and to help inform decisions by international agencies, funders, and vaccine manufacturers, we conducted an impact and cost-effectiveness analysis examining 20 rotavirus vaccine use cases. We evaluated several currently licensed LORVs, one neonatal oral NGRV (oNGRV), one iNGRV, and one iNGRV-DTP (iNGRV comprising part of a DTP-containing combination) over a ten-year timeframe in 137 low- and middle-income countries. The most promising use case identified was a high efficacy iNGRV-DTP, predicted to have the lowest vaccine program cost (US 2.7 billion health-care cost averted), and most favorable cost-effectiveness (cost-saving). iNGRV-DTP vaccine remained the most affordable, safe, and cost-effective option even when it was assumed to have equivalent efficacy to the current LORVs. This study shows that while the development of iNGRVs with superior efficacy to currently licensed LORVs would be ideal, iNGRVs with similar efficacy to LORVs would offer substantial public health value. It also highlights the economic value of accelerating the development of DTP-based combination vaccines that include iNGRV to provide rotavirus protection.
... 10 A study conducted in 45 countries found that the timeliness of children's vaccination varies widely between and particularly within countries, and published yearly estimates of national coverage do not capture these variations. 22 Though, vaccine delay has been a long-standing issue, there are only few studies conducted to estimate and understand the demand and supply-side dynamics of delay in basic vaccination. Using the District Level Health Survey 3 (DLHS 3) survey data, it was found that only 30% of vaccinated infants received the measles vaccine at the recommended age of 9 months and only 31% of infants received DPT-3 vaccine at the recommended age of 14 weeks. ...
Aim
Timely vaccination is essential to achieve full potential of the vaccination especially in child population. Despite of success in increasing the coverage in India's universal immunization programme (UIP), timely vaccination remains a challenge. This study aims to understand the key socioeconomic correlates of vaccination delay and guide by charting the future course of action.
Subject & methods
This study was a part of the review conducted in four states namely Madhya Pradesh, Rajasthan, Assam and Haryana to understand the equity issues in immunization. It was a cross-sectional study where 293 mothers of children aged 12–35 months were interviewed using semi-structured questionnaire. Association of delay in immunization and co-variates were examined through multilevel Poisson regression framework.
Results
Timely vaccination was poor for most of the antigens except Measles. Only 52.6% of children had BCG on time and very few for Pentavalent doses as per the scheduled time (Penta-1: 3.4%, Penta-2: 1.4% and Penta-3: none). Whereas, measles showed better coverage (75%) for timely vaccination as compared to other basic antigens. About 72.7% received their basic vaccination in first year of life. Religion and mother's education were found to be associated with delay in all vaccination as per the schedule (at Birth, 6 weeks, 10 weeks, 14 weeks and 9–12 month).
Conclusion
Timeliness of vaccination definitely requires attention to avoid increased risk of infection among children and avoid epidemics and outbreaks. There is a need to increase attention towards urban areas and improve the timeliness of vaccination and utilise the complete potential of the Universal Immunisation Programme (UIP).
Bordetella pertussis is the causative agent of pertussis or whooping cough, an acute and highly contagious respiratory infection that can have serious and fatal complications such as pneumonia, encephalopathy, and seizures, especially for newborns. The disease is endemic not only in the European Union (EU)/European Economic Area (EEA) but also globally. Larger outbreaks are anticipated every three to five years, even in countries where vaccination rates are high. Despite the high pertussis vaccination coverage in developed countries and a low rate of pertussis incidence for many years, especially during the COVID-19 pandemic, the incidence of pertussis has been on the rise again, with outbreaks in some places, which is referred to as “re-emergence of pertussis”. The aim of this review is to underscore the critical importance of achieving high vaccination coverage, particularly among pregnant women, to safeguard vulnerable neonates from pertussis during their early months, before they are eligible for vaccination. This aligns with the need to address diagnostic challenges, mitigate disease severity, and strengthen public health strategies in light of the ongoing 2024 Bordetella pertussis resurgence.
Previous research has shown that parents' vaccination readiness, as measured by the 7C vaccination readiness scale, helps to understand whether and why parents are (not) willing to vaccinate their children. However, there is a lack of research investigating the association between parents' vaccination readiness and their children's actual vaccine uptake. Addressing this gap, we examined how Danish parents' level of vaccination readiness is associated with their child's vaccination status combining survey with official registry data. Specifically, parents residing in Denmark (N = 2941, 64 % female) completed a survey assessing their level of vaccination readiness with the 7C vaccination readiness scale for parents, trust in different sources of information on vaccination, and certainty about vaccinating their child with the next vaccine in the program. Additionally, official vaccination registry data on various recommended child vaccinations was obtained and matched to the survey data of their parents. Results from logistic regression analyses indicate that parents' readiness to vaccinate their children was substantially associated with completion of children's vaccination doses. More precisely, a one-point increase in parents' vaccination readiness score was associated with a two-fold increase in the likelihood of the child being vaccinated with the three main vaccines in the program. The results also show associations between each of the 7C factors, trust items, and demographic variables with real behavior as well as parents' certainty to vaccinate their children in the future. The findings further substantiate the usefulness of assessing parental vaccination readiness, with potential implications for intervention planning by researchers and policymakers.
In the United States, trust in science and medical professionals has been degrading since 2019. This has been further exasperated by the COVID-19 pandemic, where an infodemic of information existed which the public struggled to navigate, and people have generally uncertain feelings about overall human health. For decades, researchers have investigated public trust in scientists and medical professionals, often finding racial minorities feel higher distrust amongst medical professionals and associated institutions stemming from past injustices and ill-treatments. These are furthered when there is a noticeable difference in presentation or appearance between doctor and patient. At the same time, life-saving advancements in medical research (such as a novel vaccine) exist simultaneously alongside this plethora of information, sparking a misunderstanding in appropriate behaviors and responses for situations which arise such as a pandemic. This chapter discusses some background related to the role of medical professionals and scientists in vaccine acceptance and hesitancy.
The persistence of measles in many countries demonstrates large immunity gaps, resulting from incomplete or ineffective immunization with measles-containing vaccines (MCVs). MCV impact is determined, in part, by vaccination age. Infants who receive dose 1 (MCV1) at older ages have a reduced risk of vaccine failure, but also an increased risk of contracting infection before vaccination. Here, we designed a new method—based on a mathematical transmission model incorporating realistic vaccination delays and age variations in MCV1 effectiveness—to capture the MCV1 age risk trade-off and estimate the optimal age for recommending MCV1. We applied this method to a range of synthetic populations representing lower- and higher-income populations. We predict a large heterogeneity in the optimal MCV1 ages (range: 6–20 months), contrasting the homogeneity of observed recommendations worldwide. Furthermore, we show that the optimal age depends on the local epidemiology of measles, with a lower optimal age predicted in populations having lower vaccination coverage or suffering higher transmission. Overall, our results suggest the scope for public health authorities to tailor the recommended schedule for better measles control.
Background
Globally, each year, about 3 million deaths among children are prevented by pentavalent vaccinations. However, in developing countries, particularly in Sub-Saharan Africa, pentavalent vaccination dropout rates are not well reported. Therefore, this study aimed to assess pentavalent vaccination dropout rates and their determinants among under-five children in Sub-Saharan Africa.
Methods
Data from the recent Demographic and Health Surveys in 33 Sub-Saharan African countries were used for analysis. The study used a total of 358,529 under-five children. The determinants of pentavalent vaccination dropout were determined using a multilevel mixed-effects logistic regression model. Significant factors associated with pentavalent vaccination dropout were declared significant at p-values < 0.05. A model with the lowest deviance and highest logliklihood ratio was selected as the best-fit model.
Results
In Sub-Saharan Africa, one in five under-five children had pentavalent vaccination dropout rates. Factors such as Age (AOR = 1.61, 95 % CI: 1.51, 1.72), educational level (AOR = 1.30, 95 % CI: 1.22, 1.40), place of delivery (AOR = 1.65, 95 % CI: 1.57, 1.73), ANC visits (AOR = 1.34, 95 % CI: 1.23, 1.45), postnatal check-up (AOR = 1.19, 95 % CI: 1.14, 1.25), wealth status (AOR = 1.09, 95 % CI: 1.04, 1.15), distance to health facility (AOR = 1.08, 95 % CI: 1.03, 1.13), media exposure (AOR = 1.12, 95 % 1.15), and geographical region (AOR = 1.60, 95 % CI: 1.49, 1.72) had higher odds of pentavalent vaccination dropouts.
Conclusions
Pentavalent vaccination dropout rates in sub-Saharan Africa among under-five children were high. Both individual and community-level variables were determinants of pentavalent vaccination dropout rates. Government and ministry of health in Sub-Saharan Africa should give attention to those mothers of under-five children who reported distance as a big problem in accessing health facilities and to women who do not utilise antenatal and postnatal check-ups while designing policies and strategies in sub-Saharan Africa.
Background
Tanzania is 1 of 20 countries where the majority of unvaccinated and undervaccinated children reside. Prior research identified substantial rural-urban disparities in the coverage and timeliness of childhood vaccinations in Tanzania, with children in rural settings being more likely to receive delayed or no vaccinations. Further research is necessary to identify effective and scalable interventions that can bridge rural-urban gaps in childhood vaccination while accounting for multifaceted barriers to vaccination.
Objective
This protocol describes a type 1 effectiveness-implementation hybrid study to evaluate Chanjo Kwa Wakati (timely vaccination in Kiswahili), a community-based digital health intervention to improve vaccination timeliness. The intervention combines human resources (community health workers), low-cost digital strategies (electronic communication, digital case management, and task automation), a vaccination knowledge intervention, and insights from behavioral economics (reminders and incentives) to promote timely childhood vaccinations.
Methods
The study will be conducted in 2 predominantly rural regions in Tanzania with large numbers of unvaccinated or undervaccinated children: Shinyanga and Mwanza. Forty rural health facilities and their catchment areas (clusters) will be randomized to an early or delayed onset study arm. From each cluster, 3 cohorts of mother-child dyads (1 retrospective cohort and 2 prospective cohorts) will be enrolled in the study. The timeliness and coverage of all vaccinations recommended during the first year of life will be observed for 1200 children (n=600, 50% intervention group children and n=600, 50% nonintervention group children). The primary effectiveness outcome will be the timeliness of the third dose of the pentavalent vaccine (Penta3). Quantitative surveys, vaccination records, study logs, fidelity checklists, and qualitative interviews with mothers and key informants will inform the 5 constructs of the reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) framework. The results will be used to develop an implementation blueprint to guide future adaptations and scale-up of Chanjo Kwa Wakati.
Results
The study was funded in August 2022. Data collection is expected to last from February 2024 to July 2027.
Conclusions
This study will address the lack of rigorous evidence on the effectiveness of community-based digital health interventions for promoting vaccination coverage and timeliness among children from sub-Saharan Africa and identify potential implementation strategies to facilitate the deployment of vaccination promotion interventions in low- and middle-income countries.
Trial Registration
ClinicalTrials.gov NCT06024317; https://www.clinicaltrials.gov/study/NCT06024317
International Registered Report Identifier (IRRID)
PRR1-10.2196/52523
Objectives
We estimated the global impact of rotavirus vaccines on deaths among children under five years old by year.
Methods
We used a proportionate outcomes model with a finely disaggregated age structure to estimate rotavirus deaths prevented by vaccination over the period 2006-2019 in 186 countries. We ran deterministic and probabilistic uncertainty analyses and compared our estimates to surveillance-based estimates in 20 countries.
Results
We estimate that rotavirus vaccines prevented 139,000 under-five rotavirus deaths (95% uncertainty interval 98,000-201,000) in the period 2006-2019. In 2019 alone, rotavirus vaccines prevented 15% (95% uncertainty interval 11-21%) of under-five rotavirus deaths (0.5% of child mortality). Assuming global use of rotavirus vaccines and coverage equivalent to other co-administered vaccines could prevent 37% of under-five rotavirus deaths (1.2% of child mortality). Our estimates were sensitive to the choice of rotavirus mortality burden data and several vaccine impact modeling assumptions. The World Health Organization's recommendation to remove age restrictions in 2012 could have prevented up to 17,000 rotavirus deaths in the period 2013-2019. Our modeled estimates of rotavirus vaccine impact were broadly consistent with estimates from post-vaccination surveillance sites.
Conclusion
Rotavirus vaccines have made a valuable contribution to global public health. Enhanced rotavirus mortality prevention strategies are needed in countries with high mortality in under-5-year-old children.
Background:
New prevention strategies for respiratory syncytial virus (RSV) are emerging, but it is unclear if they will be cost-effective in low- and middle-income countries. We evaluated the potential impact and cost-effectiveness of two strategies to prevent RSV disease in young children in Vietnam.
Methods:
We used a static cohort model with a finely disaggregated age structure (weeks of age <5 years) to calculate the RSV disease burden in Vietnam, with and without a single dose of maternal vaccine (RSVpreF, Pfizer) or of monoclonal antibody (Nirsevimab, Sanofi, Astra Zeneca). Each strategy was compared to no pharmaceutical intervention, and to each other. We assumed both strategies would be administered year round over a ten-year period. The primary outcome measure was the cost per disability-adjusted life year (DALY) averted, from a societal perspective. We ran probabilistic and deterministic uncertainty analyses.
Results:
With central input assumptions for RSVpreF vaccine (25/dose, 77 % efficacy, 5 months protection), both options had similar cost-effectiveness (3367 per DALY averted) when compared separately to no pharmaceutical intervention. RSVpreF vaccine had a lower net cost than Nirsevimab (net discounted cost of 264 m) but prevented fewer RSV deaths (24 % versus 31 %). Our results were very sensitive to assumptions about the dose price, efficacy, and duration of protection. At $5/dose and a willingness-to-pay threshold of 0.5 times the national GDP per capita, both prevention strategies are cost-effective.
Conclusions:
RSVpreF vaccine and Nirsevimab may be cost-effective in Vietnam if appropriately priced.
Background:
Deaths due to vaccine-preventable diseases are one of the leading causes of death among African children. Vaccine coverage is an essential measure to decrease infant mortality. The COVID-19 pandemic has affected the healthcare system and may have disrupted vaccine coverage.
Methods:
DTP third doses (DTP3) Vaccine Coverage was extracted from UNICEF databases from 2012 to 2021 (the last available date). Joinpoint regression was performed to detect the point where the trend changed. The annual percentage change (APC) with 95% confidence intervals (95% CI) was calculated for Africa and the regions. We compared DTP3 vaccination coverage in 2019-2021 in each country using the Chi-square test.
Result:
During the whole period, the vaccine coverage in Africa increased with an Annual Percent change of 1.2% (IC 95% 0.9-1.5): We detected one joinpoint in 2019. In 2019-2021, there was a decrease in DTP3 coverage with an APC of -3.5 (95% -6.0; -0,9). (p < 0.001). Vaccination rates decreased in many regions of Sub-Saharan Africa, especially in Eastern and Southern Africa. There were 26 countries (Angola, Cabo Verde, Comoros, Congo, Côte d'Ivoire, Democratic Republic of the Congo, Djibouti, Ethiopia, Eswatini, The Gambia, Guinea-Bissau, Liberia, Madagascar, Malawi, Mauritania, Mauritius, Mozambique, Rwanda, Senegal, Seychelles, Sierra Leone, Sudan, Tanzania, Togo, Tunisia, Uganda, and Zimbabwe) where the vaccine coverage during the two years decreased. There were 10 countries (Angola, Cabo Verde, Comoros, Democratic Republic of the Congo, Eswatini, The Gambia, Mozambique, Rwanda, Senegal, and Sudan) where the joinpoint regression detected a change in the trend.
Conclusions:
COVID-19 has disrupted vaccine coverage, decreasing it all over Africa.
Health agencies rely upon survey-based physical measures to estimate the prevalence of key global health indicators such as hypertension. Such measures are usually collected by non-healthcare worker personnel and are potentially subject to measurement error due to variations in interviewer technique and setting, termed "interviewer effects". In the context of physical measurements, particularly in low- and middle-income countries, interviewer-induced biases have not yet been examined. Using blood pressure as a case study, we aimed to determine the relative contribution of interviewer effects on the total variance of blood pressure measurements in three large nationally-representative health surveys from the Global South.
We utilized 169,681 observations between 2008 and 2019 from three health surveys (Indonesia Family Life Survey, National Income Dynamics Study of South Africa, and Longitudinal Aging Study in India). In a linear mixed model, we modeled systolic blood pressure as a continuous dependent variable and interviewer effects as random effects alongside individual factors as covariates. To quantify the interviewer effect-induced uncertainty in hypertension prevalence, we utilized a bootstrap approach comparing sub-samples of observed blood pressure measurements to their adjusted counterparts. Our analysis revealed that the proportion of variation contributed by in- terviewers to blood pressure measurements was statistically significant but small: approximately 0.24-2.2% depending on the cohort. Thus, hypertension prevalence estimates were not substantially impacted at national scales. However, individual extreme interviewers could account for measurement divergences as high as 12%. Thus, highly biased interviewers could have important impacts on hypertension estimates at the sub-district level.
Several reasons affecting childhood immunization such as parents' objection, disagreement or concern about immunization safety, long distance walking, long waiting time at health facilities are the most common reasons for incomplete vaccination/ immunization. Lack of access to immunization services contributed to low immunization coverage as results of negative health workers' attitudes. Socioeconomic factors such as mother's education, husband occupation and family's monthly income. Lack of awareness on the importance of immunization.
Background
The COVID-19 pandemic has disrupted health systems globally. We estimated the effect of the pandemic on the coverage and timeliness of routine childhood immunization in India through April 2021.
Methods
We used data from India’s National Family Health Survey 2019-2021 (NFHS-5), a cross-sectional survey which collected immunization information of under-five children from a nationally representative sample of households between June 2019 and April 2021. We used a mother fixed-effects regression model – accounting for secular trends and confounding factors – to compare COVID-affected children with their COVID-unaffected siblings (n=59,144). Children who were eligible for a vaccine after January 30, 2020 (date of the first COVID case in India) were considered as the COVID-affected group and those eligible for a vaccine after this date were included in the COVID-unaffected group. Coverage of the following vaccine doses was considered—Bacillus Calmette–Guérin (BCG), hepatitis B birth dose (hepB0), DPT1 (diphtheria, pertussis, and tetanus, first dose), DPT2, DPT3, polio1, polio2, polio3, and measles first dose (MCV1). Indicators of vaccine coverage and vaccine timeliness (defined as receiving a dose within 45 days of minimum eligibility age) were separately examined.
Findings
Immunization coverage was lower in COVID-affected children as compared with unaffected children, ranging from 2% lower for BCG and hepB0 to 9% for DPT3 and 10% for polio3. There was no significant difference in MCV1 coverage. Coverage reduction was greater for vaccines doses given at later age groups. The rate of timely receipt of polio and DPT vaccine doses was 3%-5% lower among COVID-affected children relative to unaffected children. Among population subgroups, COVID-affected male children and those from rural areas experienced the highest reduction in vaccine coverage.
Interpretation
Children in India experienced lower routine immunization coverage and greater delays in immunization during the COVID-19 pandemic.
Funding
The Bill & Melinda Gates Foundation.
Objectives
To evaluate the cost-effectiveness of alternative rotavirus vaccines in Niger, using UNIVAC, a proportionate outcomes model.
Setting
The study leverages global, regional and local data to inform cost-effectiveness modelling. Local data were collected as part of a clinical trial taking place in the Madarounfa district, Maradi region, Niger.
Participants
The study models impact of infants vaccination on rotavirus gastroenteritis in children under 5 years of age.
Interventions
We compared the use of ROTARIX (GlaxoSmithKline, Belgium), ROTAVAC (Bharat Biotech, India) and ROTASIIL (Serum Institute, India) to no vaccination and to each other over a 10-year period starting in 2021.
Results
We estimated that ROTARIX, ROTAVAC and ROTASIIL would each prevent 13 million cases and 20 000 deaths of children under 5 years over a 10-year period in Niger. Compared with no vaccination, the cost to avert a disability-adjusted life-year was US107 with ROTASIIL and US100 willingness-to-pay threshold.
Conclusions
This study can inform decision-making around rotavirus vaccination policy in Niger, demonstrating that ROTAVAC is likely the most cost-effective option. Alternative products (ROTASIIL and ROTARIX) may also be considered by decision-makers if they are priced more competitively, or if their cold chain requirements could bring additional economic benefits.
Background
Timely vaccination maximizes efficacy for preventing infectious diseases. In the absence of national vaccination registries, representative sample survey data hold vital information on vaccination coverage and timeliness. This study characterizes vaccination coverage and timeliness in Tanzania and provides an analytic template to inform contextually relevant interventions and evaluate immunization programs.
Methods
Cross-sectional data on 6,092 children under age 3 from the 2015–16 Tanzania Demographic and Health Survey were used to examine coverage and timeliness for 14 vaccine doses recommended in the first year of life. The Kaplan-Meier method was used to model time to vaccination. Cox proportional hazard models were used to examine factors associated with timely vaccination.
Results
Substantial rural–urban disparities in vaccination coverage and timeliness were observed for all vaccines. Across 14 recommended doses, documented coverage ranged from 52 % to 79 %. Median vaccination delays lasted up to 35 days; gaps were larger among rural than urban children and for later doses in vaccine series. Among rural children, median delays exceeded 35 days for the 3rd doses of the polio, pentavalent, and pneumococcal vaccines. Median delays among urban children were < 21 days for all doses. Among rural and urban children, lower maternal education and delivery at home were associated with increased risk of delayed vaccination. In rural settings, less household wealth and greater distance to a health facility were also associated with increased risk of delayed vaccination.
Discussion
This study highlights persistent gaps in uptake and timeliness of childhood vaccinations in Tanzania and substantial rural–urban disparities. While the results provide an informative situation assessment and outline strategies for identifying unvaccinated children, a national electronic registry is critical for comprehensive assessments of the performance of vaccination programs. The timeliness measure employed in this study—the amount of time children are un- or undervaccinated—may serve as a sensitive performance metric for these programs.
Empiric studies exploring the timeliness of routine vaccination in low-and middle-income countries (LMICs) have gained momentum in the last decade. Nevertheless, there is emerging evidence suggesting that these studies have key measurement and methodological gaps that limit their comparability and utility. Hence, there is a need to identify, and document these gaps which could inform the design, conduct, and reporting of future research on the timeliness of vaccination. We synthesised the literature to determine the methodological and measurement gaps in the assessment of vaccination timeliness in LMICs. We searched five electronic databases for peer-reviewed articles in English and French that evaluated vaccination timeliness in LMICs, and were published between 01 January 1978, and 01 July 2021. Two reviewers independently screened titles and abstracts and reviewed full texts of relevant articles, following the guidance framework for scoping reviews by the Joanna Briggs Institute. From the 4263 titles identified, we included 224 articles from 103 countries. China (40), India (27), and Kenya (23) had the highest number of publications respectively. Of the three domains of timeliness, the most studied domain was ‘delayed vaccination’ [99.5% (223/224)], followed by ‘early vaccination’ [21.9% (49/224)], and ‘untimely interval vaccination’ [9% (20/224)]. Definitions for early (seven different definitions), untimely interval (four different definitions), and delayed vaccination (19 different definitions) varied across the studies. Most studies [72.3% (166/224)] operationalised vaccination timeliness as a categorical variable, compared to only 9.8% (22/224) of studies that operationalised timeliness as continuous variables. A large proportion of studies [47.8% (107/224)] excluded the data of children with no written vaccination records irrespective of caregivers’ recall of their vaccination status. Our findings show that studies on vaccination timeliness in LMICs has measurement and methodological gaps. We recommend the development and implement of guidelines for measuring and reporting vaccination timeliness to bridge these gaps.
Background
We determined the risk factors associated with unvaccinated children in rural Gambia.
Methods
We conducted prospective demographic surveillance and recorded immunisations in real time in the Upper River Region, The Gambia. Analysis included residents born from 1 January 2012 to 31 December 2016. Data included age, sex, household members and relationships, migrations, births, deaths, ethnicity, residential location and birth type. Children were defined as unvaccinated at 10, 15 and 24 mo of age if they missed all primary series doses (pentavalent, oral polio and pneumococcal conjugate vaccines), secondary series (first dose measles and yellow fever vaccines) or both vaccination series, respectively. Logistic regressions measured the association between risk factors and being unvaccinated.
Results
In total, 5% (1567/30 832) of infants born during the study period and who were residents at the age of 10 mo were unvaccinated. Being unvaccinated at 10 mo of age was associated with children; who did not reside with either parent (adjusted OR 2.26, 95% CI 1.60 to 3.19), whose parents were not the head of household (1.29, 1.09 to 1.52), who had experienced immigration (2.78, 1.52 to 5.08) or who were not of Mandinka ethnicity (between 1.57 and 1.85 for other ethnicities).
Conclusions
Family characteristics are associated with unimmunised children in rural Gambia. Our findings may inform strategies to increase vaccine coverage.
Background
Vaccines have proven to be one of the most effective strategies to control infectious diseases and contributed to childhood survival. While high vaccine coverages provide individual’s and herd immunity, age-appropriate vaccination or vaccine timeliness is important for maximum vaccine’s protection, but often not evaluated. We aimed to describe the timeliness of childhood vaccination for Indonesian infants and identify risk factors associated with delayed vaccination.
Methods
This study was a sub-study of the Indonesian Pneumonia and Vitamin D status (IPAD) study, a community-based cohort study to investigate pneumonia incidence in two districts in Yogyakarta province, Indonesia. Socio-demographic data were obtained from structured interviews and vaccine status was obtained from maternal and child health records. Timely vaccination was defined if the vaccine was received between four days or less before and within 28 days after the recommended age of vaccination.
Results
359 (85%) out of 422 IPAD participants and their immunisation records were included. Between December 2015 and December 2017, vaccination coverage was high and ranged from 96.1% (Measles) to 100% (DTP-HepB-Hib 1). However, two thirds (67%, 242/359) of all participants had received either early or late vaccines, with dose 2 IPV (40%, 143/356), dose 3 IPV (56%, 196/349) and dose 3 DTP-HepB-Hib (29%, 103/354) most delayed, and only 1% received early doses. The main risk factors for untimely vaccination were if the infant was born in a private practice versus in a public health facility (AOR 1.90; 95% CI: 1.18–3.07) and rural residence (AOR 1.84; 95% CI: 1.15–2.94).
Conclusions
Despite high vaccine coverage for Indonesian infants (>95%), two thirds (67%) of infants had untimely vaccinations, with dose 3 IPV (56%) the most delayed. Future strategies should focus on coordination between government, health care providers, and carers to ensure timely access and vaccination of infants to ensure adherence to vaccination schedules.
La vaccination représente l'un des grands succès des stratégies de santé publique. Cependant, depuis leur introduction, les vaccins ont fait l’objet de controverses. Des polémiques médiatiques ont contribué à ébranler la confiance que les citoyens portent dans la vaccination et les autorités sanitaires. Une communication transparente et fondée sur une démonstration robuste du rapport bénéfice-risque des vaccins est donc nécessaire afin d’éclairer les décisions des autorités de santé et rétablir la confiance du grand public et des professionnels de santé.Les modèles quantitatifs pour l’évaluation du rapport bénéfice-risque (qBRm) sont de plus en plus utilisés par les parties prenantes comme outils d’aide à la décision. Ces modèles fournissent une structure permettant d’incorporer des données provenant de plusieurs sources afin de quantifier et de mettre en perspective les bénéfices et les risques d’une intervention. Cependant, les autorités de santé et les laboratoires pharmaceutiques se préoccupent du manque de cadre explicite et systématique. Des initiatives se développent afin d’optimiser l’évaluation quantitative du rapport bénéfice-risque des produits de santé. Néanmoins, peu d’entre elles sont spécifiques aux vaccins.Au vu de ce contexte, ce travail de recherche avait pour vocation de proposer et de tester de nouveaux outils permettant de structurer l’évaluation quantitative du bénéfice-risque des vaccins afin d’optimiser son utilisation dans l’aide à la décision des différentes parties prenantes.Pour cela, l’objectif de la première partie de ce travail était de synthétiser les données disponibles sur les qBRm appliqués aux vaccins afin de les analyser. L’état de l’art effectué a confirmé que les qBRm étaient de plus en plus utilisés pour aider à l’évaluation du bénéfice-risque des vaccins. Les chiffres montrent une nette augmentation du nombre de publications dans ce domaine depuis le début des années 2000. Un tiers des qBRm identifiés concernait la vaccination contre le rotavirus. Cependant aucune de ces études sur le rotavirus n’avait été développée spécifiquement pour la France. L’analyse des études sélectionnées a mis en évidence des divergences en termes d’approches méthodologiques utilisées et des lacunes concernant la qualité de l’information renseignée dans les études, rendant l’interprétation et la comparaison des modèles complexes.Au cours de la deuxième partie de ce travail nous nous sommes donc attachés à proposer des axes d’amélioration. Tout d’abord nous avons conçu un guide pour améliorer la description des analyses afin d’apporter plus de transparence et de garantir ainsi une meilleure interprétation des résultats sur les qBRm appliqués aux vaccins. Puis, en l’absence d’évaluation quantitative du rapport bénéfice-risque de la vaccination contre le rotavirus en France et compte tenu des interrogations existantes autour de son intérêt, nous avons réalisé un qBRm évaluant la vaccination contre le rotavirus en France. Enfin, nous avons souhaité explorer l’utilisation d’un nouvel outil de modélisation pour le développement de qBRm appliqués aux vaccins : le Discretely Integrated Condition Event (DICE). Le DICE constitue un outil standardisé qui pourrait être utilisé par toutes les parties prenantes. L’application d’une telle interface commune à tous les qBRm pourrait faciliter leur conception, leur analyse et leur comparaison.Cependant, ces axes d’amélioration ne constituent qu’un point de départ des efforts nécessaires à réaliser pour l’évaluation du rapport bénéfice-risque des vaccins. De nouvelles initiatives sont essentielles afin de poursuivre la généralisation des qBRm appliqués aux vaccins, tout en les rendant plus performants et assortis de résultats robustes et transparents. Ces étapes semblent nécessaires pour rétablir la confiance en la vaccination et améliorer les couvertures vaccinales, assurant ainsi une protection optimale des populations face à des maladies infectieuses.
Background: Kenya introduced a pentavalent vaccine including the DTP, Haemophilus influenzae type b and hepatitis b virus antigens in Nov 2001 and strengthened immunization services. We estimated immunization coverage before and after introduction, timeliness of vaccination and risk factors for failure to immunize in Kilifi district, Kenya. Methods: In Nov 2002 we performed WHO cluster-sample surveys of > 200 children scheduled for vaccination before or after introduction of pentavalent vaccine. In Mar 2004 we conducted a simple random sample (SRS) survey of 204 children aged 9 - 23 months. Coverage was estimated by inverse Kaplan-Meier survival analysis of vaccine- card and mothers' recall data and corroborated by reviewing administrative records from national and provincial vaccine stores. The contribution to timely immunization of distance from clinic, seasonal rainfall, mother's age, and family size was estimated by a proportional hazards model. Results: Immunization coverage for three DTP and pentavalent doses was 100% before and 91% after pentavalent vaccine introduction, respectively. By SRS survey, coverage was 88% for three pentavalent doses. The median age at first, second and third vaccine dose was 8, 13 and 18 weeks. Vials dispatched to Kilifi District during 2001 - 2003 would provide three immunizations for 92% of the birth cohort. Immunization rate ratios were reduced with every kilometre of distance from home to vaccine clinic (HR 0.95, CI 0.91 - 1.00), rainy seasons ( HR 0.73, 95% CI 0.61 - 0.89) and family size, increasing progressively up to 4 children ( HR 0.55, 95% CI 0.41 - 0.73). Conclusion: Vaccine coverage was high before and after introduction of pentavalent vaccine, but most doses were given late. Coverage is limited by seasonal factors and family size
Background:
In 1999, a previous rotavirus vaccine (RotaShield; Wyeth Laboratories, Marietta, PA) was withdrawn from the US market after postlicensure monitoring identified an association with intussusception. Although the new rotavirus vaccine (RotaTeq; Merck, West Point, PA) introduced in 2006 was not associated with intussusception in prelicensure trials, additional monitoring is important to ensure a complete safety profile.
Methods:
We assessed intussusception reports after RotaTeq vaccination by using data from the Vaccine Adverse Event Reporting System and the Vaccine Safety Datalink, a cohort of children enrolled in managed care. Observed versus expected rate ratios were determined by using vaccine dose distribution data and Vaccine Safety Datalink background intussusception rates.
Results:
Between February 1, 2006, and September 25, 2007, the Vaccine Adverse Event Reporting System received 160 intussusception reports after RotaTeq vaccination. With the assumptions that reporting completeness was 75% and that 75% of the distributed doses of RotaTeq were administered, the observed versus expected rate ratios were 0.53 and 0.91 for the 1-21 and 1-7 day interval after vaccination, respectively. In the Vaccine Safety Datalink, 3 intussusception cases occurred within 30 days after 111521 RotaTeq vaccinations, compared with 6 cases after 186722 non-RotaTeq vaccinations during the same period. If, like RotaShield, RotaTeq had a 37-fold increased risk of intussusception within 3 to 7 days after vaccination, then 8 intussusception cases would be expected within 3 to 7 days among the approximately 84000 infants vaccinated with the first dose of RotaTeq in the Vaccine Safety Datalink (N = 49902) and the prelicensure trial (N = 34035) combined, whereas no cases have been observed.
Conclusions:
Available data do not indicate that RotaTeq is associated with intussusception. Although an intussusception risk similar in magnitude to that of RotaShield can be excluded, continued monitoring is necessary for complete assessment of the safety profile of RotaTeq.
For the prevention of pertussis and invasive Haemophilus influenzae type b (Hib) infections, each with a peak for mortality and serious complications in the first year of life, early vaccination is important and needs adequate monitoring. In a 1999 national coverage survey the timing of uptake of these vaccines in German children was therefore assessed conventionally at defined age thresholds and with a new adaptation of the Kaplan-Meier (KM) method estimating immunization uptake over time by 1 minus the survival function s(t). Only 6% and 9% of children were vaccinated against pertussis and Hib in accordance with the national recommended primary vaccination schedule. Coverage levels for the primary vaccination course of 50% and 90% were attained for pertussis after 6.6 and 16.3 months respectively and for Hib after 7.0 and 24.3 months. These estimates were only possible with the KM method which proved useful to monitor vaccination programmes and will allow the comparison of vaccination uptake in different populations.
To evaluate within the first 6 months of birth the immunogenicity of a 3-component acellular pertussis (aP) vaccine containing filamentous hemagglutinin (FHA), pertactine (PRN), and genetically detoxified pertussis toxin (PT) in infants who received a dose of vaccine at birth, in addition to the recommended schedule administered at 3, 5, and 11 months. Furthermore, we investigated the influence of maternal antibodies on aP vaccine response.
We used enzyme-linked immunosorbent assay to evaluate immunoglobulin G antibody levels in 45 infants immunized at birth and at 3, 5, and 11 months (group 1) and in 46 infants immunized at the ages of 3, 5, and 11 months (group 2). All mothers were also tested at delivery.
At the age of 5 months the geometric mean titer of anti-PT, anti-FHA, and anti-PRN was significantly greater in group 1 (who had received 2 doses) than in group 2 (1 dose). At 6 months geometric mean titers were significantly higher in group 1 than in group 2 for anti-PRN and anti-FHA, whereas no significant differences were observed for anti-PT.
Immunization at birth may be important for an earlier prevention of the pertussis disease in infants under 6 months, especially in Italy, where the recommended ages for aP vaccine administration are 3, 5, and 11 months.
We examined the timeliness of vaccine administration among children aged 24 to 35 months for each state of the United States and the District of Columbia.
We analyzed the timeliness of vaccinations in the 2000-2002 National Immunization Survey. We used a modified Bonferroni adjustment to compare a reference state with all other states.
Receipt of all vaccinations as recommended ranged from 2% (Mississippi) to 26% (Massachusetts), with western states having less timeliness than eastern states.
Vaccination coverage measures usually focus on the number of vaccinations accumulated by specified ages. Our analysis of timeliness of administration shows that children rarely receive all vaccinations as recommended. State health departments can use timeliness of vaccinations along with other measures to determine children's susceptibility to vaccine-preventable diseases and to evaluate the quality of vaccination programs. States can use the modified Bonferroni comparison to appropriately compare their results with other states.
Assessment of delay in age-appropriate vaccination provides more information about timeliness of vaccination than up-to-date vaccination coverage. The authors applied survival analysis methods to data from a vaccination coverage survey among children aged 13-59 months conducted in Argentina in 2002. By age 19 months, 43% of children (95% confidence interval (CI): 40, 46) were vaccinated with the fourth dose of diphtheria, tetanus, and pertussis (DTP4). By age 13 months, 55% of children (95% CI: 52, 57) were vaccinated with measles-containing vaccine. By age 7 months, 33% of children (95% CI: 27, 40) were vaccinated with the third dose of hepatitis B. Compared with firstborn children, third children were more likely to be delayed for DTP4 (relative risk (RR) = 1.41, 95% CI: 1.22, 1.62), measles-containing vaccine (RR = 1.54, 95% CI: 1.32, 1.78), and the third dose of hepatitis B (RR = 1.31, 95% CI: 1.03, 1.67). Children whose caregivers had completed secondary school were less likely to be delayed for DTP4 (RR = 0.68, 95% CI: 0.52, 0.90) compared with those whose caregivers had not completed primary school. Survival analysis methods were helpful in measuring vaccine uptake and should be considered in future surveys when assessing delay in age-appropriate vaccination.
Kenya introduced a pentavalent vaccine including the DTP, Haemophilus influenzae type b and hepatitis b virus antigens in Nov 2001 and strengthened immunization services. We estimated immunization coverage before and after introduction, timeliness of vaccination and risk factors for failure to immunize in Kilifi district, Kenya.
In Nov 2002 we performed WHO cluster-sample surveys of >200 children scheduled for vaccination before or after introduction of pentavalent vaccine. In Mar 2004 we conducted a simple random sample (SRS) survey of 204 children aged 9-23 months. Coverage was estimated by inverse Kaplan-Meier survival analysis of vaccine-card and mothers' recall data and corroborated by reviewing administrative records from national and provincial vaccine stores. The contribution to timely immunization of distance from clinic, seasonal rainfall, mother's age, and family size was estimated by a proportional hazards model.
Immunization coverage for three DTP and pentavalent doses was 100% before and 91% after pentavalent vaccine introduction, respectively. By SRS survey, coverage was 88% for three pentavalent doses. The median age at first, second and third vaccine dose was 8, 13 and 18 weeks. Vials dispatched to Kilifi District during 2001-2003 would provide three immunizations for 92% of the birth cohort. Immunization rate ratios were reduced with every kilometre of distance from home to vaccine clinic (HR 0.95, CI 0.91-1.00), rainy seasons (HR 0.73, 95% CI 0.61-0.89) and family size, increasing progressively up to 4 children (HR 0.55, 95% CI 0.41-0.73).
Vaccine coverage was high before and after introduction of pentavalent vaccine, but most doses were given late. Coverage is limited by seasonal factors and family size.
The occurrence of adverse events temporally associated with diphtheria and tetanus toxoids and pertussis vaccine (DTP) has led to consideration of a delay in the schedule of initial vaccination. We developed an inferential model estimating the changes in pertussis- and DTP-associated health outcomes that might occur if initial DTP administration were delayed from 2,4, and 6 months to 8,10, and 12 months of age. An additional 636 cases of pertussis—115 of which would be associated with complications, including two encephalopathies—were projected to occur under the proposed as compared to the current schedule. Adverse medical events attributable to the vaccine were assumed to remain unchanged following the change in schedule. We projected 353 fewer chance associations with sudden infant death syndrome but 1311 more chance associations between DTP and seizures. These estimates suggest that the current schedule of vaccinating infants at 2, 4, and 6 months of age is causally associated with less morbidity and should be continued.
(JAMA 1987;257:1341-1346)
The occurrence of adverse events temporally associated with diphtheria and tetanus toxoids and pertussis vaccine (DTP) has led to consideration of a delay in the schedule of initial vaccination. We developed an inferential model estimating the changes in pertussis- and DTP-associated health outcomes that might occur if initial DTP administration were delayed from 2, 4, and 6 months to 8, 10, and 12 months of age. An additional 636 cases of pertussis--115 of which would be associated with complications, including two encephalopathies--were projected to occur under the proposed as compared to the current schedule. Adverse medical events attributable to the vaccine were assumed to remain unchanged following the change in schedule. We projected 353 fewer chance associations with sudden infant death syndrome but 1311 more chance associations between DTP and seizures. These estimates suggest that the current schedule of vaccinating infants at 2, 4, and 6 months of age is casually associated with less morbidity and should be continued.
PIP
Infants should receive live trivalent oral poliovirus vaccine (TOPV) and DPT immunization as early in life as possible in order to minimize the time that they are at risk of contracting these vaccine-preventable diseases. Passively acquired circulating maternal antibodies provide protection in the 1st few weeks or months of life. Although these antibodies may modify or block the serum immune response during the 1st few weeks of life, the 1st or priming dose of DPT can be given effectively after 4 weeks of age. TOPV administered to infants during the 1st week of life results in intestinal infections and local immune responses in 50-100% of infants and serum antibody responses in 30-70% of infants. The serum antibody response following TOPV administration at 4-8 weeks of age is as effective as vaccine administered to older infants. The WHO Program on Immunization recommends initiating DPT and TOPV schedules at 6 weeks of age. In countries where poliomyelitis has not been controlled, TOPV should be given at birth, or at 1st contact with the health services, then at 6 weeks of age, followed by 2 additional doses 4 weeks apart. (author's)
The effect of early immunization, prior to discharge from the newborn nursery, on subsequent immunity as determined by enzyme-linked immunosorbent assay (ELISA) immunoglobulin (Ig) M and IgG antibody titers to filamentous hemagglutinin and lymphocytosis-promoting toxin (LPT) of Bordetella pertussis and by standard pertussis agglutinin titers was investigated. Eighteen infants received routine diphtheria-tetanus-pertussis (DTP) immunization at 2, 4, and 6 months of age; 17 other infants received routine immunization and an additional DTP immunization in the newborn nursery. Antibody was determined on samples of cord blood and whole blood obtained at 4, 6, and 9 months of age. IgM anti-filamentus hemagglutinin was significantly higher at 4 and 6 months of age in the group that received early immunization (P less than .05). There was no significant difference in IgM anti-LPT, IgG anti-filamentus hemagglutinin, IgG anti-LPT, or pertussis agglutinin antibodies. Six control infants had high cord IgG anti-LPT titers. These six infants had significantly lower antibody titers to LPT at 6 and 9 months of age when compared with control with control infants with lower cord titers. Thirteen infants in the early immunization group with lower cord IgG anti-LPT titers achieved significantly lower titers at 9 months of age than the 12 comparable infants in the control group.
To determine whether children attending our local health department clinics were being immunized in a timely manner, and to investigate the reasons for children not being immunized on schedule.
Cross-sectional research design.
Five Salt Lake City/County Health Department immunization clinics in Utah.
All patients presenting to the clinics for immunization from November 1990 to March 1991 when minor illness is prevalent.
Data were gathered through interview and questionnaire.
Children were mostly white; they came from two-parent households with reasonably high incomes and high parental education level. Only four children were denied vaccination, all for inappropriate timing. None were denied for illness. More than 75% had postponed bringing their children in for immunization. The most common reason given for delay was minor illness in the child.
Even in this "low-risk" population, parental misperception regarding immunizations is a significant, contributing factor to low immunization rates. Public educational programs directed at increasing parental knowledge must be developed.
Unlabelled:
In Germany the annual number of systemic Haemophilus influenzae cases in unvaccinated children aged 3-60 months has recently been exceeded by the number of cases in children vaccinated at least once with the PRP-D, HbOC or OMP vaccines, which until 1995 have almost exclusively been used for H. influenzae b (Hib) vaccination. Most of the vaccinated children however could already have had more vaccinations at onset of disease. How much does an age-related suboptimal vaccination status increase the risk for systemic H. influenzae infections? A case control study was performed in West Germany. Cases with systemic H. influenzae infections were ascertained between 7/92 and 8/ 94 with an ongoing active hospital surveillance programme. Six age-matched population controls per case were recruited at random. Only vaccinated cases and controls were included in the study. The main exposure analysed in this study was suboptimal vaccination at censoring; for censoring ages (age at disease onset in cases and corresponding age in matched controls) > 6 months: one vaccination in 1st year only; > 18 months: two (three for combined vaccines with Hib + DT or DPT in one syringe) vaccinations in the 1st year of life but no booster vaccination. Suboptimal vaccination for age increased the risk for systemic H. influenzae infections by a factor of 4.74 (95%-CI 2.17-10.34). Following adjustment for confounders the odds ratio was 4.39 (95%-CI 1.74-11.07). Subgroup analyses showed that this risk was not related to the type of vaccine used. The risk for "no booster vaccination" in children aged > 18 months appeared even greater than the risk associated with one vaccination in the 1st year only.
Conclusions:
On schedule and complete Hib vaccinations are essential for an optimal effectiveness of Hib vaccination programmes. Booster vaccinations between 12 and 18 months are important if the PRP-D, HbOC and OMP vaccines are used for primary vaccination.
In developing countries, pneumonia and meningitis due to Haemophilus influenzae type b (Hib) are common in children under age 12 months and the mortality from meningitis is high. Protein-polysaccharide conjugate vaccines have brought Hib disease under control in industrialised countries. We did a double-blind randomised trial in The Gambia to assess the efficacy of a Hib conjugate vaccine for the prevention of meningitis, pneumonia, and other invasive diseases due to Hib.
Between March, 1993, and October, 1995, 42,848 infants were randomly allocated the conjugate vaccine Hib polysaccharide tetanus protein (PRP-T) mixed with diphtheria-tetanus-pertussis vaccine (DTP), or DTP alone at age 2 months, 3 months, and 4 months. Children who presented with signs of invasive Hib were investigated by blood culture and, where appropriate, by lumbar puncture, chest radiograph, or percutaneous lung aspirate. Children were followed up for between 5 and 36 months.
The median ages at which children received the study vaccine were 11 weeks, 18 weeks, and 24 weeks. 83% of children enrolled received all three doses of vaccine. 17 cases of culture-positive Hib pneumonia, 28 of Hib meningitis, and five of other forms of invasive Hib disease were detected amongst the study children. The efficacy of the vaccine for the prevention of all invasive disease after three doses was 95% (PRP-T vaccinees 1, controls 19 [95% CI 67-100]), for the prevention of Hib pneumonia after two or three doses, 100% (vaccinees 0, controls 10 [55-100]), and for the prevention of radiologically defined pneumonia at any time after enrollment, 21.1% (PRP-T vaccinees 198, controls 251 [4.6-34.9]).
PRP-T conjugate Hib vaccine prevented most cases of meningitis and pneumonia due to Hib in Gambian infants. The reduction in the overall incidence of radiologically defined pneumonia in PRP-T vaccinees suggests that about 20% of episodes of pneumonia in young Gambian children are due to Hib. The introduction of Hib vaccines into developing countries should substantially reduce childhood mortality due to pneumonia and meningitis.
Vaccination status is assessed nationally in terms of up-to-date status without regard to the age at which recommended doses were actually received. Our study was conducted in 2000-2001 using the most current National Health Interview Survey (NHIS) public use files available.
Retrospective analysis to determine up-to-date and age-appropriate vaccination status for children aged 25 to 72 months. Five years of pooled data (1992-1996) were obtained from the NHIS Immunization Supplement for children aged 25 to 72 months with immunization data based on written records. The outcome measures used were months of vaccination delay relative to age-appropriate vaccination standard as well as up-to-date vaccination status for the fourth diphtheria-tetanus-pertussis (DTP 4), Polio3, the first measles-mumps-rubella (MMR1) doses, and the 4:3:1 series.
Of the 9223 eligible children, 80% were up-to-date for the 4:3:1 vaccination series, but 48% had experienced delays relative to age-appropriate standards. For the DTP4 dose, 85% were up-to-date, although only 46% had received this dose at the appropriate age. Similarly, 90% of children were up-to-date with their Polio3 dose, with 64% receiving this dose at the appropriate age; 96% were up-to-date for the MMR1, and 58% received this dose at the appropriate age. Age-appropriate DTP4 vaccination increased by 17 percentage points from 1992 to 1996, whereas up-to-date DTP4 status increased by only 6% during the same period.
Children with up-to-date vaccination status often experienced considerable delay relative to age-appropriate vaccination standards. Consequently, vaccination status measures based solely on up-to-date status tend to understate the degree of underimmunization in a population. National surveillance of age-appropriate vaccination is necessary to identify subpopulations with the greatest prevalence of vaccination delay and to reveal underlying trends that may not be evident through assessments of up-to-date status.
Research on physical activity and the physical environment is at the correlates stage, so it is premature to attribute causal effects. This paper provides a conceptual approach to understanding how the physical design of neighborhoods may influence behavior by disentangling the potential effects of income, university education, poverty, and degree of urbanization on the relationship between walking to work and neighborhood design characteristics.
The study merges Canadian data from 27 neighborhood observations with information on walking to work from the 1996 census. Hierarchical linear modeling was used to create a latent environment score based on 18 neighborhood characteristics (e.g., variety of destinations, visual aesthetics, and traffic). The relationship between the environment score and walking to work was modeled at the second level, controlling for income, university education, poverty, and degree of urbanization.
With the exceptions of visual interest and aesthetics, each neighborhood characteristic contributed significantly to the environment score. The environment score was positively associated with walking to work, both with and without adjustment for degree of urbanization. Controlling for university education, income, and poverty did not influence these relationships.
The positive association between the environment score and walking to work, controlling for degree of urbanization supports the current movement toward the development of integrated communities for housing, shops, workplaces, schools, and public spaces. Given the need for research to guide environmental interventions, collaboration among public health practitioners, urban planners, and transportation researchers is essential to integrate knowledge across sectors.
In most countries, pertussis surveillance is inadequate for accurately estimating numbers of cases or deaths. Good estimates are needed to help set priorities for vaccination programmes. We aimed to develop a simple, reliable, and explicit method for estimating pertussis cases and deaths for children under 15 years to calculate the global disease burden in 1999. We estimated the proportion of susceptible children becoming infected in countries with poor vaccination coverage (<70%) in 1999 at 30% by 1 year, 80% by 5 years, and 100% by 15 years of age and for countries with good coverage (> or =70%) at 10% by 1 year, 60% by 5 years, and 100% by 15 years. Vaccine efficacy was estimated at 80% for preventing infection and 95% for preventing deaths. We used UN population estimates and vaccination coverage reported to WHO (adjusted for specific survey data if available). Case fatality ratios for countries with high and low child mortality were derived from published and unpublished work. For some countries with good vital events registration we used reported deaths adjusted for underascertainment. In 1999 there were an estimated 48.5 million pertussis cases in children worldwide. Deaths from pertussis were estimated at 390000 and at 295000 after adjustment for local data sources. Based on this approach, disability-adjusted life years from pertussis (12.7 million) in 2000 exceeded those of other preventable diseases such as lung cancer (11.4 million) and meningitis (5.8 million). This simple approach yields estimates that can be used for setting vaccination programme priorities. Better data are needed on the public health importance of pertussis in high mortality countries, the benefits of incomplete vaccination, and the harm from delayed vaccination.
Over the last seven years, and especially in 2001, a declining coverage for MMR vaccination in 2-year-olds has been noted in Sweden. By recording actual date of vaccination in a cohort of almost 4,000 children in a county in central Sweden, we found that parents' decision to postpone vaccination by up to 1.5 years beyond the stipulated age of 18 months accounted for about half the reported drop in 2001. Even if coverage thus improves with time, postponed vaccination adds to the pool of unprotected children in the population. The design of the current national surveillance system overestimates coverage at 2 years and fails to record delayed vaccination. To avoid future outbreaks that can appear around imported cases of measles it is crucial to attain high coverage levels by timely vaccination.
Only 18% of children in the United States receive all vaccinations at the recommended times or acceptably early.
To determine the extent of delay of vaccination during the first 24 months of life.
The 2003 National Immunization Survey was conducted by random-digit dialing of households and mailings to vaccination providers to estimate vaccination coverage rates for US children aged 19 to 35 months. Data for this study were limited to 14,810 children aged 24 to 35 months.
Cumulative days undervaccinated during the first 24 months of life for each of 6 vaccines (diphtheria and tetanus toxoids and acellular pertussis; poliovirus; measles, mumps, and rubella; Haemophilus influenzae type b; hepatitis B; and varicella) and all vaccines combined, number of late vaccines, and risk factors for severe delay of vaccination.
Children were undervaccinated a mean of 172 days (median, 126 days) for all vaccines combined during their first 24 months of life. Approximately 34% were undervaccinated for less than 1 month and 29% for 1 to 6 months, while 37% were undervaccinated for more than 6 months. Vaccine-specific undervaccination of more than 6 months ranged from 9% for poliovirus vaccine to 21% for Haemophilus influenzae type b vaccine. An estimated 25% of children had delays in receipt of 4 or more of the 6 vaccines. Approximately 21% of children were severely delayed (undervaccinated for more than 6 months and for > or vaccines). Factors associated with severe delay included having a mother who was unmarried or who did not have a college degree, living in a household with 2 or more children, being non-Hispanic black, having 2 or more vaccination providers, and using public vaccination provider(s).
More than 1 in 3 children were undervaccinated for more than 6 months during their first 24 months of life and 1 in 4 children were delayed for at least 4 vaccines. Standard measures of vaccination coverage mask substantial shortfalls in ensuring that recommendations are followed regarding age at vaccination throughout the first 24 months of life.
Using incidence rates from CDC's Active Bacterial Core surveillance and immunogenicity data from the Navajo/Apache trial of pneumococcal conjugate vaccine (PCV), we used Markov modeling to predict the optimal age to give a single dose of PCV. Antibody concentration thresholds of 0.35 and 1.0 mcg/ml were considered protective. Our outcome was vaccine serotype-specific invasive pneumococcal disease (IPD) incidence at 24 months. The models predicted the optimal age to vaccinate is 5-7 months with vaccine-induced immunologic memory and 8-10 months without memory. IPD reduction ranged from 15 to 62%, depending on model parameters. A single PCV dose in infants could prevent substantial IPD.
Whereas immunization coverage has been repeatedly assessed in the Swiss population, little is known about the timely administration of universally recommended immunizations in Switzerland and elsewhere. The goal of this study was to determine compliance with official standard immunization recommendations in pre-school and school-aged children in Basel, Switzerland, focusing on coverage rates and timely administration. Of a cohort of children entering kindergarten and third-grade primary school in Basel in 2001, 310 and 310, respectively, were identified in proportion to the overall age-appropriate populations in the four city districts. Foreign-born children were excluded. The data were extracted from immunization records provided voluntarily by parents. Coverage for three doses of diphtheria, tetanus, and poliomyelitis vaccines was >95% and <90% for pertussis and Hib. The rates of age-appropriate booster doses were significantly lower, especially for pertussis and Hib (<60%). Cumulative coverage for measles, mumps, and rubella (MMR) was <90% for the first dose and 33% for the second dose by 10 years of age. All immunizations were administered with significant delays. Coverage for the first three doses of DTP combination vaccines did not reach 90% before 1 year of age and, for the first dose of MMR, a plateau just below 80% was not reached before 3 years of age. Delayed administration of immunizations in childhood, as well as complete lack of booster doses in a significant fraction of children, with important implications for public health have been discovered in this study. This may lead to fatal disease in individuals, epidemics in the community, and threatens national and international targets of disease elimination, such as measles and congenital rubella syndrome.
There are few data, especially outside the United States, examining the timeliness of childhood vaccination, although it is of key importance for diseases such as pertussis, and invasive disease due to Haemophilus influenzae type b and Streptococcus pneumoniae. The aim of this study was to use the unique resource of the Australian Childhood Immunisation Register (ACIR) to examine trends in and factors associated with timeliness of infant vaccination at the national level. As in previous studies, age-appropriate immunisation was defined as within 30 days of the recommended age. Vaccination delays became more common for later doses, given at an older age, but long delay (greater than 6 months) occurred in only 1-2%. Although immunisation coverage increased over time, timeliness did not improve. Among Indigenous infants, long delays occurred in 5-12% of those residing in very remote areas, but by 2 years of age, overall immunisation coverage was similar to non-Indigenous children. With immunisation coverage at the key indicator ages of 12 and 24 months now high in most industrialised countries including Australia, timeliness of vaccine doses should be the next benchmark to aim for in program performance, especially in specific sub-groups such as Indigenous children who stand to gain most from prevention of early onset disease.
In Germany, Haemophilus influenzae type b (Hib), polio and hepatitis B (HBV) vaccines have been combined with diphtheria, tetanus and acellular pertussis vaccines. We examined whether the use of combination vaccines has improved the timing of these vaccinations.
Vaccination information was obtained from representative nationwide telephone interviews about 2701 children born from 1996 through 2003 in Germany. We assessed up-to-date vaccination as the percentage of children vaccinated by 3, 5 and 15 months for the first dose, full primary series and full immunization, respectively. We compared results over periods when different combination vaccines were used. We also compared median age at first dose, full priming and full immunization for children receiving different types of combination vaccines.
During the study period, monovalent vaccines were replaced by higher-valent combination vaccines. With the change from mono- to 4-, 5- and 6-valent vaccines, up-to-date vaccination increased for Hib, polio and HBV. Median age at immunization improved by 0.5 month for Hib, 0.4 month for polio and 0.9 month for HBV at the first dose and 2.2 months for Hib, 3.2 months for polio and 1.4 months for HBV at full immunization when comparing hexavalent with monovalent vaccines. Median age for 4-5-valent vaccines was intermediate. The difference between monovalent and 6-valent vaccines remained significant after stratifying/adjusting for the effect of birth cohorts.
Combination vaccines are usually advocated for reducing the number of injections. In Germany, however, the use of combination vaccines has also significantly improved timeliness of immunizations.
This report is a revision of General Recommendations on Immunization and updates the 2002 statement by the Advisory Committee on Immunization Practices (ACIP) (CDC. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices and the American Academy of Family Physicians. MMWR 2002;51[No. RR-2]). This report is intended to serve as a general reference on vaccines and immunization. The principal changes include 1) expansion of the discussion of vaccination spacing and timing; 2) an increased emphasis on the importance of injection technique/age/body mass in determining appropriate needle length; 3) expansion of the discussion of storage and handling of vaccines, with a table defining the appropriate storage temperature range for inactivated and live vaccines; 4) expansion of the discussion of altered immunocompetence, including new recommendations about use of live-attenuated vaccines with therapeutic monoclonal antibodies; and 5) minor changes to the recommendations about vaccination during pregnancy and vaccination of internationally adopted children, in accordance with new ACIP vaccine-specific recommendations for use of inactivated influenza vaccine and hepatitis B vaccine. The most recent ACIP recommendations for each specific vaccine should be consulted for comprehensive discussion. This report, ACIP recommendations for each vaccine, and other information about vaccination can be accessed at CDC's National Center for Immunization and Respiratory Diseases (proposed) (formerly known as the National Immunization Program) website at http//:www.cdc.gov/nip.
Delayed vaccination against childhood diseases may lead to increased mortality and morbidity among children and also affect the fraction of vaccinated population necessary for elimination of a disease. The purpose of this study was to assess the extent of the delay in vaccinations in four countries belonging to Commonwealth of Independent States and to assess how the timeliness of vaccination affects the vaccination coverage. The fraction of children vaccinated with delay was substantial in all the studied countries, and the impact of differences between countries was stronger than individual risk factors assessed in this study. In presence of vaccination delay, up-to-date vaccination is a biased estimator of the fraction of vaccinated population. Age-appropriate vaccination should be taken into account when assessing vaccination coverage.
Our goal was to predict, using delayed diphtheria-tetanus-acellular pertussis vaccination as an indicator, whether the current narrowly defined age limits for pentavalent rotavirus vaccine exclude a substantial proportion of children from complete immunization against rotavirus and to assess adherence of providers to recommended age limits by examining the first 6 months of use of pentavalent rotavirus vaccine in Philadelphia, Pennsylvania.
Data from a computerized children's immunization registry in Philadelphia were analyzed. Demographics and age at immunization with first 3 diphtheria-tetanus-acellular pertussis doses were examined from 2001 to 2005. Similar characteristics were evaluated for children who received pentavalent rotavirus vaccine doses during the first 6 months of its availability (August 2006 through January 2007).
During the 5-year period, 24 403 of 103 967 recipients of first diphtheria-tetanus-acellular pertussis vaccine were >12 weeks of age; only 56 411 of 79 564 first diphtheria-tetanus-acellular pertussis recipients <or=12 weeks of age received the first 3 doses at ages that they could have completed the pentavalent rotavirus vaccine series if vaccines were given at the same visit. Children using public providers were more likely to have delayed immunization. During the first 6 months of pentavalent rotavirus vaccine implementation, 5566 pentavalent rotavirus vaccine doses were recorded in the Kids Immunization Database/Tracking System: 3912 first doses, 1419 second doses, and 235 third doses. Of 3912 first-dose pentavalent rotavirus vaccine recipients, 770 were >12 weeks of age. Hospital-based providers were less likely to administer pentavalent rotavirus vaccine off-label.
With the current level of vaccine implementation and current pentavalent rotavirus vaccine recommendations for series initiation, a substantial proportion of children are expected to be excluded from receiving any pentavalent rotavirus vaccine or completing the series. In the first 6 months of availability, pentavalent rotavirus vaccine frequently was used off-label for age, underscoring the importance of education of immunization providers. Current outreach programs for finding 10-month-old toddlers delinquent for immunizations will not improve the possibility of protection against rotavirus.
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