Invasive pneumococcal diseases in birth cohorts vaccinated with PCV-7 and/or PHiD-CV in the province of Quebec, Canada
ABSTRACT The 10-valent protein D pneumococcal conjugate vaccine (PHiD-CV) was licensed on the basis of immunogenicity studies and there are no published data on its effectiveness to prevent invasive pneumococcal disease (IPD). In the province of Quebec, Canada, PHiD-CV was introduced in the summer of 2009, replacing the 7-valent CRM197 vaccine (PCV-7). Transition to the new vaccine was recommended regardless of the number of PCV7 doses already administered.
IPD rates in children born in 2007-2010 and observed up to the end of 2010 were computed from laboratory surveillance data. The main vaccine used for the infant primary immunization series (mainly 2 doses at 2-4 months) and the toddler (12 months) booster dose was inferred from the Quebec City Immunization Registry data.
IPD rates were significantly lower in the cohorts exposed to PHiD-CV (35/100,000 person-years) as compared with those exposed to PCV-7 (64/100,000person-years; p=0.03). There was no breakthrough vaccine-type IPD case among children who had received ≥2 PHiD-CV doses for the primary series or a single PHiD-CV dose as a booster. There was also a statistically non-significant lower frequency of 19A and other non-vaccine types IPD cases in children exposed to 2+1 PHiD-CV doses as compared with those exposed to PCV-7.
Results are compatible with a high level of protection induced by PHiD-CV against IPD caused by homologous serotypes.
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ABSTRACT: The ten-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Finnish National Vaccination Program (NVP) in September 2010 with a 2+1 schedule (3, 5, 12 months) without catch-up vaccinations. We evaluated the direct and indirect effects of PCV10 on invasive pneumococcal disease (IPD) among children ≤5 years of age during the first three years after NVP introduction. We conducted a population-based, observational follow-up study. The cohort of vaccine-eligible children (all children born June 1, 2010 or later) was followed from 3 months of age until the end of 2013. For the indirect effect, another cohort of older children ineligible for PCV10 vaccination was followed from 2011 through 2013. Both cohorts were compared with season- and age-matched reference cohorts before NVP introduction. National, population-based laboratory surveillance data were used to compare culture-confirmed serotype-specific IPD rates in the vaccine target and reference cohorts by using Poisson regression models. The overall IPD rate among vaccine-eligible children was reduced by 80% (95%CI 72 to 85); the reduction in vaccine-type IPD was 92% (95%CI 86 to 95). However, a non-significant increase in non-vaccine type IPD was observed. During 2012-2013, we also observed a 48% (95%CI 18 to 69) reduction in IPD among unvaccinated children 2 to 5 years of age, which was mostly attributable to the ten vaccine serotypes. This is the first population-based study investigating the impact of PCV10 introduction without prior PCV7 use. A substantial decrease in IPD rates among vaccine-eligible children was observed. A smaller and temporally delayed reduction among older, unvaccinated children suggests that PCV10 also provides indirect protection against vaccine-type IPD. Changes in serotype distribution warrant continuous monitoring of potential increases in non-vaccine serotypes.PLoS ONE 10(3):e0120290. DOI:10.1371/journal.pone.0120290 · 3.53 Impact Factor
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ABSTRACT: Objetivos avaliar os possíveis efeitos da introdução da vacina pneumocócica conjugada 10 valente no calendário vacinal no Paraná sobre os casos de meningite pneumocócica; avaliar a distribuição dos sorotipos dentre os casos. Método estudo observacional, transversal, com coleta de dados retrospectiva dos casos de meningite pneumocócica no Estado do Paraná, notificados ao SINAN, no período de 1998 a 2011. Foram analisados 1339 casos de meningite pneumocócica e comparados os 1205 casos do período pré-vacina (1998 a 2009) com os 134 do período pós-vacina (2010 a 2011). A análise estatística descritiva e comparativa (teste qui-quadrado e razão de prevalência) foi realizada no software de estatística JMP 5.1.2 (JMP Statistical Discovery, Carolina do Norte, EUA) e no Programa EPI INFO 6. Resultados Observou-se redução significativa das taxas médias de incidência e mortalidade na população geral. A análise dos casos nos períodos pré e pós-vacina nas faixas etárias contempladas pela vacinação (menores de 2 anos) mostrou reduções significativas das taxas de incidência (6,01 casos/100.000 para 2,49 casos/100.000 habitantes), mortalidade (1,85 casos/100.000 habitantes para 0,47 casos/100.000 habitantes), enquanto que a letalidade média não apresentou variação significativa. Houve redução significativa dos casos cujos sorotipos estão incluídos na vacina (80,7% para 53,3%). Conclusão Mesmo com um tempo reduzido de uso, a vacina pneumocócica conjugada 10 valente já apresentou um impacto relevante na diminuição dos coeficientes de incidência e mortalidade dos casos de meningite entre os lactentes, além de redução de casos cujos sorotipos estão incluídos na vacina.Jornal de Pediatria 10/2014; 83. DOI:10.1016/j.jped.2014.07.002 · 0.94 Impact Factor
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ABSTRACT: Infection with Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide, especially in low income countries where pneumococcal conjugate vaccines (PCVs) are still underused. In countries where PCVs have been introduced, much of their efficacy has resulted from their impact on nasopharyngeal carriage in vaccinated children. Understanding the epidemiology of carriage for S. pneumoniae and other common respiratory bacteria in developing countries is crucial for implementing appropriate vaccination strategies and evaluating their impact.PLoS ONE 08/2014; 9(8):e103293. DOI:10.1371/journal.pone.0103293 · 3.53 Impact Factor