Decline in Early Childhood Respiratory Tract Infections in the Norwegian Mother and Child Cohort Study After Introduction of Pneumococcal Conjugate Vaccination

Department of Chronic Diseases, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
The Pediatric Infectious Disease Journal (Impact Factor: 3.14). 05/2012; 31(9):951-5. DOI: 10.1097/INF.0b013e31825d2f76
Source: PubMed

ABSTRACT The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced into the Norwegian Childhood Immunization Program in 2006. A substantial effectiveness of PCV7 immunization against invasive pneumococcal disease has been demonstrated, whereas evidence of its impact on respiratory tract infections are less consistent.
This study included children participating in the Norwegian Mother and Child Cohort Study, which recruited pregnant women between 1999 and 2008. Maternal report of acute otitis media (AOM), lower respiratory tract infections (LRTIs) and asthma in the child was compared by PCV7 immunization status, as obtained from the Norwegian Immunization Registry. Generalized linear models with the log-link function were used to report adjusted relative risks (RRs) and 95% confidence intervals (CIs).
For children who had received 3 or more PCV7 immunizations by 12 months of age, the adjusted RRs of AOM and LRTIs between 12 and 18 months were 0.86 (95% CI: 0.81, 0.91) and 0.78 (95% CI: 0.70, 0.87) respectively, when compared with nonimmunized children. A reduced risk of AOM, RR 0.92 (95% CI: 0.90, 0.94), and LRTIs, RR 0.75 (95% CI: 0.71, 0.80), between 18 and 36 months of age was also identified among children who had received 3 or more immunizations by 18 months of age. No association was seen between PCV7 immunization and asthma at 36 months of age.
Reduced incidences of AOM and LRTIs before 36 months of age were observed among children immunized with PCV7 through the childhood immunization program.

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    ABSTRACT: Background: The widespread use of 7-valent pneumococcal conjugate vaccine (PCV7) has changed acute otitis media (AOM) bacteriology. Only scattered data with regards to this effect of PCV13 have been published so far. Methods: We retrospectively identified children younger than 6 years of age who presented to our hospital with AOM, and had middle ear fluid (MEF) cultures obtained during tympanocentesis or from spontaneous otorrhea during 2008-2013, when PCV7 (2009) and PCV13 (2010) were gradually introduced in the Israeli National Immunization Program (NIP). Data were extracted for demographics, clinical and microbiological parameters, according to vaccination status. Results: Of the 295 eligible AOM episodes reported in 279 children, 224 (76%) had MEF cultures from tympanocentesis and 71 (24%) from spontaneous otorrhea. Boys and children under 2 years of age contributed 178 (60%) and 219 (74%) AOM episodes, respectively. Acute mastoiditis complicated 58 (20%) of these episodes. None of the children were PCV immunized in 2008, but >90% had received ≥1 PCV dose(s) by 2011 or later. Of the 106 (36%) MEF cultures which tested positive for otopathogens, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and multiple bacteria grew in 60 (57%), 39 (37%), 2 (2%) and 5 (5%) episodes, respectively. S. pneumoniae positive MEF culture rate in unimmunized children (31, 69%) was significantly higher than in PCV7- (22, 59%) or PCV13- (12, 50%) immunized children, p=0.04 and p=0.02, respectively. Conclusion: PCV7 and PCV13 implementations in the Israeli NIP were associated with a rapid reduction of "severe" pneumococcal AOM episodes.
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    ABSTRACT: Acute otitis media (AOM) is a very common respiratory infection in early infancy and childhood. The marginal benefits of antibiotics for AOM in low-risk populations in general, the increasing problem of bacterial resistance to antibiotics and the huge estimated direct and indirect annual costs associated with otitis media (OM) have prompted a search for effective vaccines to prevent AOM. To assess the effect of pneumococcal conjugate vaccines (PCVs) in preventing AOM in children up to 12 years of age. We searched CENTRAL (2013, Issue 11), MEDLINE (1995 to November week 3, 2013), EMBASE (1995 to December 2013), CINAHL (2007 to December 2013), LILACS (2007 to December 2013) and Web of Science (2007 to December 2013). Randomised controlled trials (RCTs) of PCVs to prevent AOM in children aged 12 years or younger, with a follow-up of at least six months after vaccination. Two review authors independently assessed trial quality and extracted data. We included 11 publications of nine RCTs (n = 48,426 children, range 74 to 37,868 per study) of 7- to 11-valent PCV (with different carrier proteins). Five trials (n = 47,108) included infants, while four trials (n = 1318) included children aged one to seven years that were either healthy (one study, n = 264) or had a previous history of upper respiratory tract infection (URTI), including AOM. We judged the methodological quality of the included studies to be moderate to high. There was considerable clinical diversity between studies in terms of study population, type of conjugate vaccine and outcome measures. We therefore refrained from pooling the results.In three studies, the 7-valent PCV with CRM197 as carrier protein (CRM197-PCV7) administered during early infancy was associated with a relative risk reduction (RRR) of all-cause AOM ranging from -5% in high-risk children (95% confidence interval (CI) -25% to 12%) to 7% in low-risk children (95% CI 4% to 9%). Another 7-valent PCV with the outer membrane protein complex of Neisseria meningitidis (N. meningitidis) serogroup B as carrier protein, administered in infancy, did not reduce overall AOM episodes, while a precursor 11-valent PCV with Haemophilus influenzae (H. influenzae) protein D as carrier protein was associated with a RRR of all-cause AOM episodes of 34% (95% CI 21% to 44%).A 9-valent PCV (with CRM197 carrier protein) administered in healthy toddlers was associated with a RRR of (parent-reported) OM episodes of 17% (95% CI -2% to 33%). CRM197-PCV7 followed by 23-valent pneumococcal polysaccharide vaccination administered after infancy in older children with a history of AOM showed no beneficial effect on first occurrence and later AOM episodes. In a study in older children with a previously diagnosed respiratory tract infection, performed during the influenza season, a trivalent influenza vaccine combined with placebo (TIV/placebo) led to fewer all-cause AOM episodes than vaccination with TIV and PCV7 (TIV/PCV7) when compared to hepatitis B vaccination and placebo (HBV/placebo) (RRR 71%, 95% CI 30% to 88% versus RRR 57%, 95% CI 6% to 80%, respectively) indicating that CRM197-PCV7 after infancy may even have negative effects on AOM. Based on current evidence of the effects of PCVs for preventing AOM, the licensed 7-valent CRM197-PCV7 has modest beneficial effects in healthy infants with a low baseline risk of AOM. Administering PCV7 in high-risk infants, after early infancy and in older children with a history of AOM, appears to have no benefit in preventing further episodes. Currently, several RCTs with different (newly licensed, multivalent) PCVs administered during early infancy are ongoing to establish their effects on AOM. Results of these studies may provide a better understanding of the role of the newly licensed, multivalent PCVs in preventing AOM. Also the impact on AOM of the carrier protein D, as used in certain pneumococcal vaccines, needs to be further established.
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    ABSTRACT: Background Data on the burden of pneumococcal disease and the most frequent serotypes demonstrated that invasive disease and pneumonia were important manifestations affecting children under 5 years of age. Therefore, pneumococcal diseases prevention became a public health priority. Uruguay was the first Latin American country to incorporate PCV7 into its National Immunization Program. The aim of this study is to compare the incidence rates for hospitalized pneumonia in children from the pre PCV introduction period and the following five years of PCVs application in Uruguay. Methods and Findings Population-based surveillance of pneumonia hospitalization rates, in children, less than 14 years of age, had been performed prior pneumococcal vaccination, and continued following PCV7 introduction and PCV13 replacement, using the same methodology. Hospitalized children with pneumonia were enrolled from January 1, 2009 through December 31st, 2012. The study was carried out in an area with a population of 238,002 inhabitants of whom 18, 055 were under five years of age. Patients with acute lower respiratory infections for whom a chest radiograph was performed on admission were eligible. Digitalized radiographs were interpreted by a reference radiologist, using WHO criteria. Pneumonia was confirmed in 2,697 patients, 1,267 with consolidated and 1,430 with non consolidated pneumonia of which incidence decrease, between 2009 and 2012, was 27.3% and 46.4% respectively. 2001–2004 and 2009–2012 comparison showed a significant difference of 20.4% for consolidated pneumonia hospitalizations. A significant incidence decline was recorded among children 6 to 35 months of age. Conclusions An overall significant reduction in pneumonia hospitalizations was observed following the introduction of PCV7 and furthermore following the change to PCV13.
    PLoS ONE 06/2014; 9(6):e98567. DOI:10.1371/journal.pone.0098567 · 3.53 Impact Factor