Impact of Ten-Valent Pneumococcal Conjugate Vaccination on Invasive Pneumococcal Disease in Finnish Children – A Population-Based Study

Abstract

BackgroundThe 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.MethodsWe 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.ResultsThe 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.ConclusionsThis 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.

Pneumococcal Conjugate Vaccine and Clinically Suspected Invasive Pneumococcal Disease

“…CI: 100-144), which was more than twofold compared with laboratoryconfirmed IPD (50 per 100 000 person-years). 5 We noted reductions for all the individual ICD-10 codes, except for A49.9 and the rarely used M00.9, and B95.5.…”

“…[1][2][3][4] In Finland, the evaluation of the impact of the 10-valent pneumococcal conjugate vaccine (PCV10) in the national vaccination program showed that the relative rate reduction in culture-confirmed invasive disease among vaccineeligible children was 80%, and the absolute reduction was 50 cases per 100 000 person-years. 5 A cluster-randomized Finnish Invasive Pneumococcal disease (FinIP) trial was conducted in Finnish infants during 2009-2010. 6 The primary aim of the trial was to assess the effectiveness of PCV10 (Synflorix, GlaxoSmithKline Vaccines, Rixensart, Belgium) against laboratoryconfirmed IPD using data collected through the National Infectious Diseases Register.…”

“…We compared the target cohort to 2 season-and age-matched (ages 3-42 months) reference cohorts combined and selected a priori from calendar years 2003 to 2008 before the national vaccination program (Fig 1). 5 The calendar period January 2009 to August 2010 was excluded from the cohort analysis because of the FinIP trial. 6 …”

“…The national vaccination program impact on culture-confirmed IPD based on the National Infectious Diseases Register data has been published previously. 5 On the basis of register records, we developed 2 case definitions with different sensitivity 7 :…”

Safety profile of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV)

“…Effectiveness against vaccine serotype IPD was demonstrated for 3+1 (100%) and 2+1 (92%) infant schedules in a clusterrandomized double-blind study in Finland (Finnish Invasive Pneumococcal disease trial, FinIP) [5]. PHiD-CV also reduced IPD incidences in post-marketing studies in Canada, Brazil, and Finland [6][7][8]. In the Pneumococcal Otitis Efficacy Trial of the 11-valent predecessor to PHiD-CV, efficacy against AOM episodes caused by NTHi was 35% [9].…”