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Tropical Medicine and
Infectious Disease
Article
Coverage, Timelines, and Determinants of Incomplete
Immunization in Bangladesh
Nurnabi Sheikh 1, Marufa Sultana 1,2 ID , Nausad Ali 1, Raisul Akram 1,
Rashidul Alam Mahumud 1,3, Muhammad Asaduzzaman 4ID and Abdur Razzaque Sarker 1, 5, *
1Health Economics and Financing Research, International Centre for Diarrhoeal Disease Research,
Bangladesh (icddr,b), 68, Shaheed Tajuddin Sarani, Dhaka 1212, Bangladesh;
nurnabi.sheikh@icddrb.org (N.S.); marufa@icddrb.org (M.S.); nausad.ali@icddrb.org (N.A.);
raisul.akram@icddrb.org (R.A.); Rashed.Mahumud@usq.edu.au (R.A.M.)
2School of Health and Social Development, Deakin University, Melbourne, Burwood, VIC 3125, Australia
3School of Commerce, University of Southern Queensland, Toowoomba, QLD 4350, Australia
4Laboratory Sciences & Services Division, International Centre for Diarrhoeal Disease Research,
Dhaka 1212, Bangladesh; asaduzzaman@icddrb.org
5Department of Management Science, University of Strathclyde, Glasgow G4 0QU, UK
*Correspondence: arazzaque@icddrb.org or razzaque.sarker@gmail.com; Tel: +88-01819262262
Received: 8 May 2018; Accepted: 20 June 2018; Published: 25 June 2018
Abstract:
Immunization has become one of the major contributors to public health globally as it
prevents communicable disease, particularly in children. The objective of this study was to estimate
the extent of timely immunization coverage and to investigate the determinants of incomplete
and untimely vaccination. Methods: The study used data from the latest Bangladesh Demographic
Health Survey (BDHS) 2014. A total sample of 1631 children aged 12–23 months who had an Expanded
Program on Immunization (EPI) card and immunization history were analyzed. Multivariable logistic
regression models were used to determine the significant influencing factors on untimely vaccination
(BCG, pentavalent vaccine/OPV, and measles) and incomplete vaccination. The results were
presented in terms of adjusted odds ratio (AOR) with a 95% confidence interval and a significance
level p< 0.05. Results: The proportions of children who received timely vaccinations were 24% for
BCG, 46% for pentavalent 3, and 53% for measles, whereas 76%, 51%, and 36% children failed to
receive the BCG, pentavalent 3, and measles vaccines, respectively, in a timely manner. The proportion
of early vaccination was 3% for pentavalent 3 and 12% for measles. Several significant influencing
factors including age, maternal education and working status, awareness of community clinics,
socioeconomic status, and geographic variation significantly contributed to untimely and incomplete
vaccination of children in Bangladesh. Conclusions: The study identified some key determinants
of untimely and incomplete childhood vaccinations in the context of Bangladesh. The findings will
contribute to the improvement of age-specific vaccination and support policy makers in taking the
necessary control strategies with respect to delayed and early vaccination in Bangladesh.
Keywords: Bangladesh; childhood disease; immunization; timeliness; low vaccination coverage
1. Introduction
Immunization has become one of the major contributors to public health globally as it prevents
communicable disease, especially among children. The Expanded Program on Immunization (EPI)
was established in early 1974 to provide all basic vaccines and to immunize every child around
the world [
1
]. The EPI is a well acknowledged and cost-effective public health intervention that
contributes to the reduction of morbidity and mortality worldwide [
2
–
4
]. Despite the success
Trop. Med. Infect. Dis. 2018,3, 72; doi:10.3390/tropicalmed3030072 www.mdpi.com/journal/tropicalmed
Trop. Med. Infect. Dis. 2018,3, 72 2 of 14
of EPI, approximately 1.5 million children die each year from vaccine-preventable diseases [
5
].
Vaccine-preventable diseases remain a potential public health problem in South-East Asia (including
Bangladesh) and sub-Saharan Africa because of early or delayed, incomplete, and low vaccination
coverage [
6
]. Bangladesh has had a successful history of immunization and is able to achieve
high vaccination coverage against vaccine-preventable diseases. However, the crude vaccination
coverage is based on the number of vaccinated children in a specified age cohort (12–23 months) only;
it does not indicate the maintenance of scheduled vaccination, though it is also recommended [
7
].
The negative consequences of early immunization include failure to generate a protective antibody
response against vaccine-preventable diseases [
8
], while delayed immunization takes longer and the
child remains susceptible to disease during infancy [
9
]. It is also evident that the effectiveness
of immunization programs tends to be reduced due to delayed vaccination [
10
]. Further, early
received doses are also considered as invalid; though very few children receive early as compared
to delayed vaccination [
10
]. In spite of substantial improvements in maternal and child health
and high crude coverage of vaccination, under-five child mortality is still 46 per 1000 live births
in Bangladesh [
11
]. The possible reasons include incomplete vaccination and relatively long delays
in timely vaccine administration, which is strongly associated with the increased risk of mortality
among children [
12
]. To maintain the quality of immunization services, the World Health Organization
(WHO) recommended improving monitoring and surveillance systems involving age-appropriate
vaccinations in low-and-middle income countries (LMICs), including Bangladesh [
5
]. Therefore, it is
necessary to prioritize and monitor the immunization program efficiently in order to reduce delayed
and incomplete vaccination and ensure the benefits of immunization.
Though it is crucial for public health aspects in Bangladesh, limited studies are available to
generate evidence about the socio-demographic factors associated with incomplete and untimely
vaccination. Furthermore, the available studies focus on specified geographical administrative
settings rather than the nation-wide scale [
13
,
14
]. However, a few studies have been conducted
in neighboring countries [
15
–
17
], and thus our study may generate evidence that could also be
useful for comparison with other settings and to address the knowledge gap. This study utilized the
nationwide Demographic and Health Survey (DHS) dataset which provides reliable information on
individual-level immunization coverage, timelines, and incomplete vaccination as well as a range of
factors that might influence immunization practices. The objective of this study was to estimate the
extent of timely immunization coverage and to investigate the determinants of incomplete and failure
of timely vaccination.
2. Materials and Methods
2.1. Data Source
The study used country representative data from the latest Bangladesh Demographic
Health Survey (BDHS), 2014. The survey was designed to provide up-to-date information on
socio-demographic, maternal, and child health indicators, including individual level vaccination
coverage and timeliness for better future planning and interventions [
11
]. Childhood vaccination
information was collected for all surviving children over the last five-year period. Immunization
data were collected based on availability of child health card and maternal recall in those cases when
the mother was not able to show child health card or immunization history was not available in the
card [
11
]. Written consent was obtained from the respondents during the interviews. The DHS dataset
is one of the largest publicly-available datasets; a mailed consent was taken from the DHS website
before conducting this study.
2.2. Study Design and Data Collection
A two-stage cluster sampling technique was designed to cover the entire population residing in
non-institutional dwelling units in Bangladesh, and the BDHS 2014 was based on a cross-sectional
Trop. Med. Infect. Dis. 2018,3, 72 3 of 14
study design. A complete list of enumeration areas (EAs) was used as a sampling framework for BDHS
2014 to cover the whole country, as provided by the Bangladesh Bureau of Statistics (BBS) [
11
]. In
the first stage of sampling, 600 EAs were selected, where 207 were in urban and 393 in rural areas
with probability proportional to the EA size. The second stage of sampling involved in selecting 30
households per cluster using a systematic random sampling technique. The survey was implemented
from June to November 2014 and data were collected from the selected 17,863 ever-married women
aged 15–49 years. A proper sampling weight was used to make the sample more representative of
the population at the national level [
9
,
11
]. More about the sampling procedure and data collection
technique of the BDHS 2014 has been described elsewhere [11].
2.3. EPI History and Schedule
Expanded Program on Immunization (EPI) is a priority program of the Government of Bangladesh
(GOB) that introduced vaccinations against six preventable diseases (tuberculosis; diphtheria, pertussis,
and tetanus; polio; and measles) in 1979. After that, the EPI integrated the hepatitis B (HepB)
vaccine, which was primarily initiated in 2003 and was then expanded in 2005 to all districts. The
Haemophilus influenzae type B (Hib) vaccine was introduced in 2009, and the measles and rubella
vaccine in 2012 [
11
]. Based on the Bangladesh immunization guidelines, children are considered
as fully vaccinated when they have received one dose of the vaccine against tuberculosis, Bacille
Calmette-Guerin (BCG), three doses of a pentavalent vaccine (DPT, Hib, and HepB), three doses of
the polio vaccine (excluding the polio vaccine given at birth), and one dose of the measles and rubella
vaccine. If children are not able to receive any one of the recommended doses than they are considered
as partially vaccinated [
11
]. The recommended vaccination schedule for Bangladesh is one dose of BCG
at birth or on first contact with health workers, the first dose of penta (penta1) and OPV1 at 6 weeks,
penta2 and OPV2 at 10 weeks, penta3 and OPV3 at 14 weeks, and the measles vaccination at 9 months
(270 days) of age (Table 1). The intervals between doses (i.e., dose 1 to dose 2 and similarly dose 2 to
dose 3) for the pentavalent vaccine and OPV are 4 weeks, respectively, as per the vaccination schedule.
Table 1.
The Expanded Program on Immunizations (EPI) schedule and timeliness in Bangladesh. Hib:
Haemophilus influenzae type B.
Diseases Vaccine Recommended
Age Period Timely Early Late
Childhood tuberculosis
(TB)/poliomyelitis
Bacille Calmette-
Guerin (BCG) At birth/0 day 0–28 days - >28 days
Diphtheria/tetanus/pertussis/
Hepatitis B/Hib pneumonia
and meningitis
Pentavalent 1 42 days 39–70 days <39 days >70 days
Pentavalent 2 70 days 67–98 days <67 days >98 days
Pentavalent 3 98 days 95–126 days <95 days >126 days
Poliomyelitis
Oral polio
vaccine (OPV) 1 42 days 39–70 days <39 days >70 days
OPV 2 70 days 67–98 days <67 days >98 days
OPV 3 98 days 95–126 days <95 days >126 days
Measles Measles 273 days 270–301 days <270 days >301 days
2.4. Immunization Coverage and Timeliness
In this analysis, children aged 12–23 months were included to capture the full vaccination
coverage and children aged above 23 months were excluded because there was a greater chance
of unavailability of EPI cards. Vaccination histories for all vaccines were coded as dummy responses
based on whether or not children had received vaccines; in this case we considered the EPI card
and also historical recall data when the EPI card was unavailable. Children who were younger than
recommended age for each vaccine were excluded from the calculation of immunization coverage.
To determine vaccination timeliness, we considered the EPI card of respective children with available
vaccination history. Vaccine timeliness was categorized into timely, early, and delayed based on the
Trop. Med. Infect. Dis. 2018,3, 72 4 of 14
recommended age of vaccination. Timely vaccination was considered as having received particular
vaccines within the recommended age, early vaccination was defined if vaccines were administered
prior to the recommended age, and late vaccination was defined if vaccines were administered after
the recommended age. However, late and early vaccination were also categorized into three different
groups to further explore about early and late vaccinations. Early vaccination categorized as less than
2 weeks early, 2–3 weeks early, and more than 3 weeks early, and, similarly, late vaccination as less than
2 months late, 3–6 months late, and more than 6 months late, respectively. These categories may help
better policy formulation to prevent age-appropriate delays. We also performed sensitivity analysis to
calculate immunization timeliness.
2.5. Explanatory Variables
The selection of the different determinants from the BDHS dataset was based on prior knowledge
and published literature. These included age, gender, birth order, birth size, birth seasons, household
size, wealth, residence, antenatal care seeking, maternal education and employment status, exposure
to electronic media, and geographic location. Birth seasons of the children were categorized as
summer (March–June), rainy (July–September), and winter (November–February) based on the
seasons of Bangladesh, taking into account the birth place as the home and the corresponding health
facility/institution. Birth size was recoded based on mothers’ recollections as normal if the mother
perceived an average size or larger, and small/poor if mother perceived a small or very small size
of the child. Maternal age was categorized as <20 years, 20–34 years, and >34 years; employment
status recoded as ‘employed’ and ‘not employed/housewife’. Drinking water sources were considered
as improved (piped into dwelling, piped to yard/plot, public tap/standpipe, tube well or borehole,
protected well, rainwater, bottled water), and non-improved (unprotected well, unprotected spring,
tanker truck/cart with drum, surface water). Improved toilet facilities (slush/pour flush to piped sewer
system, flush/pour flush to septic tank, lush/pour flush to pit latrine, ventilated improved pit (VIP)
latrine, pit latrine with slab) and non-improved (facility flush/pour flush not to sewer/septic tank/pit
latrine, pit latrine without slab/open pit, hanging toilet/hanging latrine, no facility/bush/field)
were also considered. Cooking fuel types were also categorized as clean fuel (electricity, liquefied
petroleum gas (LPG), natural gas, and biogas) and polluting fuel (kerosene, coal, lignite, charcoal,
wood, straw/grass/shrubs, agricultural crops, and animal dung). Household socio-economic status
was measured based on wealth index generated by the composition of selected household assets using
principal component analysis (PCA) technique [11].
2.6. Analytical Methods
Children aged 12–23 months with an immunization card and EPI history from the BDHS child
record dataset were included in this study. However, influential, inconsistent, and missing data
were excluded from the analysis. Finally, a total sample of 1631 children aged 12–23 months who
had EPI cards and immunization histories were selected and analyzed. Descriptive statistics such
as proportion, mean, standard deviation, and frequency distribution were executed to represent
the background characteristics of the study participants. Proportions were used to present the
immunization coverage and timeliness. Multivariable logistic regression models were used to
determine the significant influencing factors for untimely vaccination (BCG, pentavalent vaccine/OPV,
and measles) and incomplete vaccination and results were presented in terms of adjusted odds
ratio (AOR) with a 95% confidence interval (CI). Before the execution of a multivariable regression
model, a bivariate analysis was conducted to trace out the significant factors and statistically significant
factors were retained in the regression models. Three separate binary logistic regression models
were used to check the effect of different relevant predictors on failure of timely vaccination for the
specific vaccines: (1) BCG; (2) pentavalent vaccine/OPV; and (3) measles. All statistical analyses were
performed using the statistical software Stata/SE 13.0 and the entire test results were compared with
95% significance level.
Trop. Med. Infect. Dis. 2018,3, 72 5 of 14
3. Results
3.1. Background Characteristics
Background characteristics of the study participants were presented in Table 2. Almost half of the
children were male (52.85%), born at home (59.66%), and lived in rural areas (74.04%), and only 38.27%
of them had undergone a confirmed health checkup from a health professional within the two months
following birth. The mean maternal age of study children was 24.38 (SD
±
5.53), the proportion of
uneducated mothers was 12.65%, 24.29% of mothers were employed, and almost 28% of them were
aware about community clinics (CC). Most of the households used polluting fuels for cooking (85.39%),
had improved drinking water sources (88.53%) and had hygienic toilet facilities (61.11%).
Table 2. Distribution of background characteristics of the study participants (n= 1631).
Variables n(%)
Sex of child
Male 862 (52.85)
Female 769 (47.15)
Birth year
2012 460 (28.21)
2013 1171 (71.79)
Birth season
Summer 537 (32.93)
Rainy 563 (34.52)
Winter 531 (32.55)
Birth order
1 657 (40.27)
2–3 767 (47.07)
4–5 151 (9.27)
>5 55 (3.39)
Place of birth
Home 973 (59.66)
Institution 658 (40.34)
Birth size
Normal 1305 (80.04)
Small/poor 325 (19.96)
Checkup of the infant from a professional
Yes 624 (38.27)
No 1006 (61.73)
Mother’s number of living children
1–2 1227 (75.26)
>2 403 (24.74)
Mother’s age (in years)
Less than 20 326 (20.00)
20–34 1227 (75.23)
35+ 78 (4.77)
Mean age (mean ±S.D.) 24.38 ±5.53
Mother’s education level
No education 206 (12.65)
Primary 459 (28.14)
Secondary 811 (49.72)
Higher 155 (9.50)
Mother’s employment status
Not employed 1234 (75.71)
Employed 396 (24.29)
Mother’s awareness of the community clinic
No 1174 (71.97)
Yes 457 (28.03)
Trop. Med. Infect. Dis. 2018,3, 72 6 of 14
Table 2. Cont.
Variables n(%)
Mother’s access to electronic media
Yes 663 (40.66)
No 968 (59.34)
Household fuel types
Clean fuel 238 (14.61)
Polluted fuel 1392 (85.39)
Source of drinking water
Improved 1444 (88.53)
Non-improved 187 (11.47)
Type of toilet
Improved 996 (61.11)
Non-improved 634 (38.89)
Household size
≤5 members 855 (52.42)
>5 members 776 (47.58)
Average household size (mean ±S.D.) 6.07 ±2.81
Wealth index
Poorest 373 (22.89)
Poorer 292 (17.93)
Middle 323 (19.80)
Richer 336 (20.59)
Richest 307 (18.80)
Residence
Urban 423 (25.96)
Rural 1207 (74.04)
Divisions
Barisal 92 (5.63)
Chittagong 349 (21.43)
Dhaka 622 (38.17)
Khulna 129 (7.89)
Rajshahi 163 (10.01)
Rangpur 146 (8.96)
Sylhet 129 (7.91)
Among all of the study children, 74%, 70%, and 65% had EPI cards with records of BCG,
pentavalent 3, and measles vaccinations, respectively (Table 3). The overall vaccination coverage
among all study children (including children who did not have EPI cards) was 98% for BCG, 91% for
pentavalent 3, and 86% for measles. Similarly, the proportion of fully immunized children was 84%,
the proportion of partially immunized children was 14%, and 2% of children had not yet received
any vaccine from the EPI schedule (Figure 1). The proportion of children who had received timely
vaccination was 24% for BCG, 46% for pentavalent 3, and 53% for measles, whereas 76%, 51%, and 36%
of children had delays in receiving the BCG, pentavalent 3, and measles vaccines, respectively (Table 3).
The proportion of children who had received early vaccination was 3% for pentavalent 3 and 12%
for measles.
Trop. Med. Infect. Dis. 2018,3, 72 7 of 14
Table 3. Adherence to the vaccination schedule for recommended vaccines in Bangladesh based on the Demographic and Health Survey (BDHS) 2014.
Vaccine Name
Time of Vaccination 1
Had
Vaccination
Card (%)
Overall
Coverage 2
(%)
Early, n(%) Timely
n(%)
Delayed, n(%)
<2 Weeks 2–3 Weeks ≥4 Weeks Total n(%) <2 Months 3–6 Months ≥7 Months Total n(%)
BCG (n= 1201) - - - - 293 (24.41) 820 (90.40) 80 (8.83) 7 (0.78) 908 (75.59) 73.64
1597 (97.90)
Pentavalent 1 (n= 1201) 11 (8.59) 15 (11.79) 100 (79.62) 126 (10.47) 754 (62.75) 207 (64.34) 108 (33.53) 7 (2.14) 322 (26.77) 73.64
1582 (97.00)
Pentavalent 2 (n= 1180) - 2 (2.82) 61 (97.18) 63 (5.30) 639 (54.18) - 457 (95.61) 21 (4.39) 478 (40.52) 72.35
1556 (95.40)
Pentavalent 3 (n= 1141) - - 31 (100.00) 31 (2.74) 527 (46.21) - 500 (85.87) 82 (14.13) 583 (51.05) 69.96
1489 (91.30)
OPV 1 (n= 1201) 12 (9.21) 15 (11.88) 99 (78.91) 125 (10.40) 754 (62.79) 206 (64.35) 107 (33.50) 7 (2.15) 322 (26.81) 73.70
1589 (97.40)
OPV 2 (n= 1180) - 2 (2.87) 60 (97.13) 62 (5.22) 639 (54.14) - 457 (95.68) 21 (4.32) 477 (40.64) 72.35
1558 (95.50)
OPV 3 (n= 1141) - - 32 (100.00) 32 (2.81) 525 (46.04) - 499 (85.82) 83 (14.18) 584 (51.16) 69.96
1491 (91.40)
Measles (n= 1053) 2 (1.42) - 122 (98.58) 124 (11.78) 551 (52.33) - - 378 (100.00) 378 (35.90) 64.56
1404 (86.10)
1Includes sample size based on availability of vaccination cards and vaccination dates; 2Includes sample size of all children.
Trop. Med. Infect. Dis. 2018,3, 72 8 of 14
Trop. Med. Infect. Dis. 2018, 3, x FOR PEER REVIEW 8 of 14
Figure 1. Vaccination status across divisions.
The proportions of partially vaccinated (30%) and non-vaccinated (8%) children were higher in
the Sylhet division, while full vaccination coverage was higher in the Rangpur division (90%)
including all recommended vaccines. However, smaller clustering frequencies for early and delay
vaccination are presented in Table 3. In most cases, early vaccination occurred more than 4 weeks
early; similarly, delayed vaccination tended to occur more than three months late, with some
exceptions.
3.2. Failure of Timely Vaccinations and Associated Factors
A number of factors were associated with the failure of the BCG, pentavalent vaccine/OPV, and
measles vaccinations. Birth seasons, maternal employment status, source of drinking water, types of
toilets, and administrative divisions play a significant role in the failure of timely BCG vaccination
(Table 4). The determining factors for the failure of timely pentavalent/OPV vaccinations are birth
place, health professional checkup, number of children in the household, maternal educational statu s,
maternal awareness of community clinics, and administrative divisions. In the case of failure of
measles vaccination, birth season and birth order, maternal educational status, wealth quintiles and
administrative divisions were significantly associated. The study found that the birth season of
children was significantly related to the failure to receive BCG and measles vaccines in a timely
manner. Children who were born in summer season were 1.53 and 1.49 times more likely to fail to
receive the BCG and measles vaccinations, respectively, in a timely manner. The likelihood of failing
to receive a timely measles vaccine was 3.11 times higher for those of higher birth order (>5) as
compared those of lower birth order (2–3), respectively. In addition, place of birth and healthcare
consultation by professionals were significantly associated with the failure to receive timely
pentavalent vaccine and OPV vaccinations. Consequently, the children who were born at home and
received healthcare checkup by professionals were 2.13 and 1.77 times more likely to fail to receive
timely pentavalent/OPV vaccines, respectively. Our results demonstrated that the number of children
in a particular household acted as an influencing factor for the failure of timely multi-dose vaccines
(pentavalent vaccine/OPV), however, such failures were not observed in single-dose vaccines such
as BCG and measles. Maternal education was significantly associated with the failure of timely
vaccination. Children of mothers who had no formal education, had completed a primary level of
education, and had completed a secondary level of education were 2.34, 2.37, and 2.15 times more
likely to have failed to receive multi-dose vaccines as compared with children of mothers who had
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
Barisal Chittagong Dhaka Khulna Rajshahi Rangpur Sylhet Overall
Not vaccinated
Fully vaccinated
Incompletely vaccinated
Figure 1. Vaccination status across divisions.
The proportions of partially vaccinated (30%) and non-vaccinated (8%) children were higher in
the Sylhet division, while full vaccination coverage was higher in the Rangpur division (90%) including
all recommended vaccines. However, smaller clustering frequencies for early and delay vaccination
are presented in Table 3. In most cases, early vaccination occurred more than 4 weeks early; similarly,
delayed vaccination tended to occur more than three months late, with some exceptions.
3.2. Failure of Timely Vaccinations and Associated Factors
A number of factors were associated with the failure of the BCG, pentavalent vaccine/OPV,
and measles vaccinations. Birth seasons, maternal employment status, source of drinking water,
types of toilets, and administrative divisions play a significant role in the failure of timely BCG
vaccination (Table 4). The determining factors for the failure of timely pentavalent/OPV vaccinations
are birth place, health professional checkup, number of children in the household, maternal educational
status, maternal awareness of community clinics, and administrative divisions. In the case of failure
of measles vaccination, birth season and birth order, maternal educational status, wealth quintiles
and administrative divisions were significantly associated. The study found that the birth season
of children was significantly related to the failure to receive BCG and measles vaccines in a timely
manner. Children who were born in summer season were 1.53 and 1.49 times more likely to fail to
receive the BCG and measles vaccinations, respectively, in a timely manner. The likelihood of failing to
receive a timely measles vaccine was 3.11 times higher for those of higher birth order (>5) as compared
those of lower birth order (2–3), respectively. In addition, place of birth and healthcare consultation
by professionals were significantly associated with the failure to receive timely pentavalent vaccine
and OPV vaccinations. Consequently, the children who were born at home and received healthcare
checkup by professionals were 2.13 and 1.77 times more likely to fail to receive timely pentavalent/OPV
vaccines, respectively. Our results demonstrated that the number of children in a particular household
acted as an influencing factor for the failure of timely multi-dose vaccines (pentavalent vaccine/OPV),
however, such failures were not observed in single-dose vaccines such as BCG and measles. Maternal
education was significantly associated with the failure of timely vaccination. Children of mothers who
had no formal education, had completed a primary level of education, and had completed a secondary
Trop. Med. Infect. Dis. 2018,3, 72 9 of 14
level of education were 2.34, 2.37, and 2.15 times more likely to have failed to receive multi-dose
vaccines as compared with children of mothers who had completed a higher level of education.
Similarly, children of unemployed mothers were significantly more likely to be at higher risk of failing
to receive the BCG and measles vaccines, respectively (AOR = 1.38, 95% CI = 1.02, 1.93 for BCG
and AOR = 1.46, 95% CI = 1.06, 2.00 for measles). However, such relationship was not observed in
scenarios of pentavalent/OPV vaccines.
Maternal awareness is another critical issue for utilization of immunization services. Children
whose mothers were not aware about community clinics were significantly (1.40 times) more likely to
have failed to receive multi-dose vaccines (AOR = 1.40, 95% CI = 1.06, 1.86). Household characteristics
such as source of drinking water and toilet facility were other factors those were significantly
associated with the failure of timely BCG immunization. Children from households with poorer
accessibility to improved drinking water and hygienic sanitation facilities were at higher risk of failing
to receive a timely BCG vaccine. Household size was another determining factor of failure of timely
immunizations. Children from households of smaller size (≤5 members) were 1.45 times more likely
not to receive the recommended BCG vaccine schedule (AOR = 1.45, 95% CI = 1.06, 1.97 and p< 0.05)
as compared to larger households. The socio-economic status of the household had a significant
impact on vaccination timeliness. The likelihood of noncompliance with the immunization schedule
for the measles vaccine was higher among children from the poorest, poorer, and middle-class
households as compared to children from the richest households. Living in the Sylhet division
was strongly associated with a higher risk of incompliance with the vaccine schedule as compared
with the children who were living in the Rangpur division. The odds of failing to receive timely BCG
and pentavalent/OPV vaccines were 7.63 and 3.15 times higher among the children who lived in the
Sylhet division, respectively, and children of the Dhaka division had a 1.84 times higher risk of failing
to receive a timely measles vaccine, as compared to children of the Rangpur division (AOR = 1.84, 95%
CI = 1.17, 2.91 and p< 0.05).
Table 4.
Factors influencing failure of timely vaccination and incomplete vaccination among children
aged 12–23 months in Bangladesh. AOR: adjusted odds ratio; CI: confidence interval.
Variables
Failure of Timely Vaccination Incomplete
Vaccination
BCG Pentavalent
Vaccine/OPV Measles
AOR (95% CI) AOR (95% CI) AOR (95% CI) AOR (95% CI)
Sex of children
Male (ref) 1.00 1.00 1.00 1.00
Female 0.92 (0.69, 1.23) 1.08 (0.84, 1.39) 1.14 (0.88, 1.47) 0.90 (0.66, 1.23)
Birth year
2012 1.06 (0.74, 1.50) 1.04 (0.75, 1.43) 1.1 (0.80, 1.53) 1.15 (0.78, 1.69)
2013 (ref) 1.00 1.00 1.00 1.00
Birth season
Summer 1.53 ** (1.04, 2.26) 0.94 (0.67, 1.31) 1.49 ** (1.05, 2.10) 1.70 ** (1.09, 2.67)
Rainy 1.27 (0.90, 1.79) 1.06 (0.78, 1.45) 1.13 (0.82, 1.55) 2.14 *** (1.45, 3.17)
Winter (ref) 1.00 1.00 1.00 1.00
Birth order
1 1.04 (0.71, 1.53) 1.16 (0.83, 1.62) 1.44 (0.97, 2.03) 1.1 (0.72, 1.67)
2–3 (ref) 1.00 1.00 1.00 1.00
4–5 0.99 (0.53, 1.87) 1.68 (0.97, 2.91) 1.20 (0.68, 2.13) 2.10 ** (1.09, 4.02)
>5 1.87 (0.70, 5.04) 2.10 (0.90, 4.88) 3.11 ** (1.29, 7.54) 1.80 (0.71, 4.58)
Place of birth
Home 1.39 (0.93, 2.07) 2.13 ** (1.50, 3.03) 0.91 (0.64, 1.30) 1.25 (0.78, 2.01)
Institution (ref) 1.00 1.00 1.00 1.00
Birth size
Normal (ref) 1.00 1.00 1.00 1.00
Small/poor 1.30 (0.89, 1.91) 1.06 (0.77, 1.47) 0.83 (0.59, 1.16) 1.21 (0.84, 1.75)
Checkup of the infant
from a professional
Yes 1.40 (0.94, 2.09) 1.77 *** (1.25, 2.51) 1.33 (0.94, 1.89) 0.93 (0.59, 1.48)
No (ref) 1.00 1.00 1.00 1.00
Trop. Med. Infect. Dis. 2018,3, 72 10 of 14
Table 4. Cont.
Variables
Failure of Timely Vaccination Incomplete
Vaccination
BCG Pentavalent
Vaccine/OPV Measles
AOR (95% CI) AOR (95% CI) AOR (95% CI) AOR (95% CI)
Number of living children
1–2 0.67 (0.41, 1.08) 1.48 ** (1.02, 2.18) 0.92 (0.60, 1.39) 1.48 (0.88, 2.51)
>2 (ref) 1.00 1.00 1.00 1.00
Mother’s age (in years)
Less than 20 1.48 (0.65, 3.41) 0.76 (0.36, 1.62) 1.15 (0.54, 2.44) 3.21 ** (1.02, 10.13)
20–34 1.34 (0.67, 2.70) 0.76 (0.40, 1.45) 1.39 (0.74, 2.62) 3.01 ** (1.05, 8.60)
35+ (ref) 1.00 1.00 1.00 1.00
Mother’s education level
No education 0.83 (0.41, 1.68) 2.34 ** (1.26, 4.35) 0.93 (0.49, 1.76) 2.25 (0.92, 5.54)
Primary 1.19 (0.65, 2.18) 2.37 *** (1.40, 4.01) 1.49 (0.87, 2.55) 2.72 ** (1.20, 6.16)
Secondary 1.16 (0.68, 1.98) 2.15 *** (1.35, 3.42) 1.20 (0.75, 1.93) 1.58 (0.72, 3.46)
Higher (ref) 1.00 1.00 1.00 1.00
Mother’s employment status
Not employed 1.38 ** (1.02, 1.93) 0.92 (0.68, 1.24) 1.46 ** (1.06, 2.00) 0.65 ** (0.46, 0.92)
Employed (ref) 1.00 1.00 1.00 1.00
Aware of the community
clinic
No 0.78 (0.57, 1.08) 1.40 ** (1.06, 1.86) 0.92 (0.69, 1.22) 1.36 (1.01, 1.96)
Yes (ref) 1.00 1.00 1.00 1.00
Access to electronic media
Yes 1.14 (0.74, 1.73) 1.26 (0.88, 1.80) 1.41 (0.98, 2.03) 1.09 (0.69, 1.74)
No (ref) 1.00 1.00 1.00 1.00
Source of drinking water
Improved (ref) 1.00 1.00 1.00 1.00
Non-improved 2.73 ** (1.03, 7.21) 0.66 (0.36, 1.21) 1.13 (0.58, 2.23) 1.46 (0.90, 2.37)
Type of toilet
Improved (ref) 1.00 1.00 1.00 1.00
Non-improved 1.42 ** (1.01, 2.03) 0.90 (0.66, 1.23) 0.77 (0.56, 1.05) 1.89 *** (1.32, 2.70)
Household size
≤5 members 1.45 ** (1.06, 1.97) 1.07 (0.81, 1.40) 1.10 (0.83, 1.46) 0.95 (0.67, 1.33)
>5 members (ref) 1.00 1.00 1.00 1.00
Wealth index
Poorest 0.55 (0.27, 1.10) 1.33 (0.72, 2.43) 1.89 ** (1.02, 3.51) 2.20 ** (1.05, 4.61)
Poorer 0.54 (0.28, 1.04) 1.16 (0.65, 2.06) 2.17 ** (1.21, 3.89) 1.26 (0.61, 2.60)
Middle 0.92 (0.52, 1.64) 1.13 (0.70, 1.84) 1.64 ** (1.01, 2.66) 1.10 (0.57, 2.14)
Richer 1.02 (0.62, 1.67) 0.8 (0.53, 1.21) 1.47 (0.97, 2.23) 1.01 (0.54, 1.84)
Richest (ref) 1.00 1.00 1.00 1.00
Residence
Urban (ref) 1.00 1.00 1.00 1.00
Rural 1.18 (0.82, 1.71) 0.95 (0.69, 1.31) 1.14 (0.82, 1.59) 0.75 (0.49, 1.15)
Divisions
Barisal 1.61 (0.86, 3.01) 1.73 (0.91, 3.29) 0.65 (0.33, 1.26) 1.7 (0.75, 3.85)
Chittagong 3.01 *** (1.85, 4.91) 1.29 (0.81, 2.05) 1.24 (0.77, 2.01) 1.5 (0.77, 2.90)
Dhaka 3.78 *** (2.40, 5.95) 0.98 (0.64, 1.52) 1.84 ** (1.17, 2.91) 1.18 (0.63, 2.23)
Khulna 4.74 *** (2.44, 9.19) 1.83 ** (1.02, 3.27) 0.75 (0.41, 1.39) 1.77 (0.81, 3.88)
Rajshahi 4.96 *** (2.73, 9.02) 1.52 (0.89, 2.60) 1.37 (0.79, 2.38) 1.62 (0.78, 3.37)
Rangpur (ref) 1.00 1.00 1.00 1.00
Sylhet
7.63 *** (3.55, 16.38)
3.15 *** (1.6, 6.18) 1.07 (0.56, 2.05) 3.76 *** (1.84, 7.67)
** p< 0.05, *** p< 0.01.
3.3. Factors of Incomplete Vaccinations
In this study, we also tried to trace the influencing factors of incomplete vaccination in Bangladesh.
Season of birth, birth order, maternal age and educational qualifications, employment status, hygienic
toilet facilities, socio-economic status, and administrative divisions were found as significant predictors
of incomplete immunization. Children who were born in the summer and rainy seasons were 1.70
and 2.14 times more likely to be incompletely vaccinated as compared to winter season, respectively.
Children whose birth order was 4–5 had 2.10 times more risk of incomplete vaccination. Comparatively,
children of the younger mothers (<20, and 20–34 years) were at (3.21 and 3.01 times) higher risk of
Trop. Med. Infect. Dis. 2018,3, 72 11 of 14
incomplete vaccination than those of older mothers (>34 years). Similarly, children of less educated
mothers (primary level) were at increased likelihood of incomplete vaccination (AOR = 2.72, 95%
CI = 1.20, 6.16, p< 0.05) than those of mothers with a higher level of education. However, maternal
employment also raises the likelihood of incomplete vaccination and children of unemployed mothers
were 0.35 times less likely to have been incompletely vaccinated. Children of households with
unhygienic toilet facilities were at 89% greater risk of incomplete vaccination (AOR = 1.89, 95%
CI = 1.32, 2.71 and p< 0.001) than their counterparts. Moreover, lower household socio-economic
status was related to higher likelihood of incomplete vaccination than higher socio-economic status.
Children from the poorest community had 2.20 times greater risk of incomplete vaccination than the
children from the richest community. Similarly, children from Sylhet division were 3.76 times more
likely to have incomplete vaccination compared with children from Rangpur division.
4. Discussion
Immunization is one of the most effective public health interventions for lowering the burden
of disease among young children and averting millions of deaths globally. However, inadequate
and incomplete immunization is a significant public health problem in resource-poor countries like
Bangladesh. When a certain portion of children receive incomplete vaccinations and/or fail to be
vaccinated in a timely manner, there is a possibility of propagating the transmission of the diseases in
society. This study put forward the determining factors of incomplete and failure of timely childhood
vaccination and contributes to the documentation of pattern of routine immunization uptake in
Bangladesh. This study identified several significant influencing factors, including age, education,
and working status of mothers, awareness of community clinic, wealth status, and geographic variation
that contribute to untimely vaccination and incomplete vaccination of children in Bangladesh.
Our study demonstrated that several factors were significantly associated with untimely
vaccination. Factors such as maternal unemployment and lower socioeconomic status (particularly in
households with no proper hygienic sanitation systems or potable drinking water) were significantly
positively associated with the failure of timely BCG vaccination. Among the determining factors, we
found that children of unemployed mothers failed to receive timely vaccinations for BCG/measles.
This finding was contradictory the findings of other settings [
18
]. One reason may be that in Bangladesh
most unemployed women are fully engaged with domestic and other non-paid work, and hence they
tend to forget their children’s vaccination timing. However, those women are also not financially
empowered, which might be another reason for not coming to the vaccination site on time. The study
found that those children who lived in lower socioeconomic strata failed to utilize the immunization
service in time and could not follow the vaccination schedules, although the timely BCG immunization
reduced mortality substantially in Bangladesh [
19
]. Seasons appeared as another potential influencing
factor, although the reason for this difference is not immediately known; future qualitative research
will be insightful. It is also noticeable that the children who were born in summer season were less
likely to receive the BCG and measles vaccinations in time.
Our study found that children who were born at home were more likely to fail to receive the
pentavalent/OPV vaccines. This is supported by previous findings, whereby children born in health
facilities had more advantages as compared to those born in households [
20
]. We found that maternal
education is a crucial factor for childhood vaccination, which is in a similar line with other studies in
that caregiver education had a positive influence on BCG and measles vaccine coverage [
20
,
21
]. As in
earlier studies, it is also noted that information barriers such as lack of awareness about community
clinics and their activities among mothers increases likelihood of not following vaccination schedules
and also the likelihood of incomplete immunization for their younger children [
16
]. Birth order is
also a determining factor of incomplete vaccination and in the case of the measles vaccination we
observed that later-born children had a higher risk of failure of timely vaccination; similar findings
were also observed in other countries [22].
Trop. Med. Infect. Dis. 2018,3, 72 12 of 14
Our study demonstrated that maternal education and age are significantly associated with
incomplete vaccination. Children of younger and less educated mothers were more likely to have
been incompletely vaccinated. Globally, similar patterns have been observed; mothers with a lower
educational level were less likely to fully utilize immunization services [
23
–
26
]. However, we found for
employed mothers, children were at greater risk of incomplete vaccination than those of unemployed
mothers. Again, lack of awareness about community clinics, unhygienic toilet facilities, and lower
socio-economic status are key factors related to incomplete vaccination. Therefore, the policymaker
should be dedicated to investing more resources to increase public awareness and motivation for the
timely use of immunization services for children. Those of lower socio-economic strata tend to be
deprived of the benefits of vaccination, either due to a lack of awareness or financial isssues i.e., time or
resource constraints to access nearby facilities for immunization [
16
]. It is already well established that
when households experience a shortage of food and resources, participation in immunization practices
becomes of lower priority [
17
]. As in an earlier study, we identified geographic barriers as another
influencing factor, both for timely use of immunization services and for complete vaccination [
16
].
According to the administrative regions of the country, the children who lived in Sylhet division were
less likely to receive timely vaccines and more likely to have been incompletely vaccinated. The Sylhet
division mostly covers a remote hilly and riverine area, and the communication system is more fragile
than other regions of the country. However, we did not capture the factors related to supply, such
as announcement of campaigns, resources for vaccinations, longer waiting periods, and distances to
vaccination sites in this administrative division, although an earlier study found that the information
barrier is one of the prime reasons for incomplete vaccination, with some geographic variations [
21
].
Therefore, proper announcement and precautionary interventions should be encouraged to prevent
incomplete vaccination and to explain the positive effects of timely vaccination so that vaccination
coverage will be improved.
The study has several limitations for interpretation of results. The study is based on secondary
data and the information and the status of child immunization based on either immunization cards or
the self-reports of women. Therefore, the potential effect of recall bias on our results cannot be ignored.
Therefore, the completeness of vaccination might be underestimated or overestimated. Further, supply
side factors were not considered in the study. However, the study results can be generalized at the
country level because the study utilized data from the latest nationally representative household survey.
Thus, our findings are still significant and relevant in drawing attention to the often neglected aspect
of untimely and/or incomplete vaccinations. Hence, a longitudinal study is suggested to explore the
factors associated with untimely and incomplete immunization for each type of vaccination.
5. Conclusions
The study identified some of the key determinants of untimely and incomplete childhood
vaccination in Bangladesh. These findings will contribute to the improvement of age-specific
vaccination and support policy makers to develop the necessary control strategies with respect to
delayed and early vaccination in Bangladesh. Targeted interventions should be urgently undertaken
in order to increase the immunization rates and optimize vaccine effectiveness. These interventions
need to focus on those of low socio-economic and educational status in order to improve knowledge
on vaccination timing.
Author Contributions:
N.S. and A.R.S. conceptualized the study. N.S., M.S. and A.R.S. performed the data
analysis and interpretation. N.S., M.S., N.A., R.A., R.A.M., M.A. and A.R.S. contributed to writing. N.S., M.S.
and A.R.S. critically reviewed the final version. All authors approved the final version of the manuscript.
Funding:
This research did not receive any specific grant from funding agencies in the public, commercial, or
not-for-profit sectors.
Acknowledgments:
ICDDR,B is thankful to the Governments of Australia, Bangladesh, Canada, Sweden and the
U.K. for providing core/unrestricted support. We would like to thank Health Economics and Financing Research
Group of ICDDR,B for their earlier comments on this research.
Trop. Med. Infect. Dis. 2018,3, 72 13 of 14
Conflicts of Interest:
The authors declares no potential conflicts of interest with respect to the research, authorship,
and/or publication of this article.
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