Impact of the 10-valent pneumococcal conjugate vaccine on hospital admissions in children under three years of age in Iceland

Samuel Sigurdsson,Elias Eythorsson,Helga Erlendsdóttir,Birgir Hrafnkelsson,Karl G Kristinsson,Ásgeir Haraldsson

doi:10.1016/j.vaccine.2020.01.094

Samuel Sigurdsson, Elias Eythorsson + Show 4 more

Open Access

https://doi.org/10.1016/j.vaccine.2020.01.094

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Abstract

IntroductionPneumococcus is an important respiratory pathogen. The 10-valent pneumococcal vaccine (PHiD-CV) was introduced into the Icelandic vaccination programme in 2011. The aim was to estimate the impact of PHiD-CV on paediatric hospitalisations for respiratory tract infections and invasive disease. MethodsThe 2005–2015 birth-cohorts were followed until three years of age and hospitalisations were recorded for invasive pneumococcal disease (IPD), meningitis, sepsis, pneumonia and otitis media. Hospitalisations for upper- and lower respiratory tract infections (URTI, LRTI) were used as comparators. The 2005–2010 birth-cohorts were defined as vaccine non-eligible cohorts (VNEC) and 2011–2015 birth-cohorts as vaccine eligible cohorts (VEC). Incidence rates (IR) were estimated for diagnoses, birth-cohorts and age groups, and incidence rate ratios (IRR) between VNEC and VEC were calculated assuming Poisson variance. Cox regression was used to estimate the hazard ratio (HR) of hospitalisation between VNEC and VEC. Results51,264 children were followed for 142,315 person-years, accumulating 1,703 hospitalisations for the respective study diagnoses. Hospitalisations for pneumonia decreased by 20% (HR 0.80, 95%CI:0.67–0.95) despite a 32% increase in admissions for LRTI (HR 1.32, 95%CI:1.14–1.53). Hospital admissions for culture-confirmed IPD decreased by 93% (HR 0.07, 95%CI:0.01–0.50) and no hospitalisations for IPD with vaccine-type pneumococci were observed in the VEC. Hospitalisations for meningitis and sepsis did not change. A decrease in hospital admissions for otitis media was observed, but did not coincide with PHiD-CV introduction. ConclusionFollowing the introduction of PHiD-CV in Iceland, hospitalisations for pneumonia and culture confirmed IPD decreased. Admissions for other LRTIs and URTIs increased during this period.

Highlights

Pneumococci are the causative agent of 9–30% of community-acquired pneumonia in children, and this proportion is higher in severe pneumonia cases [5,6,7,8,9]
This study is a single-centre, individual-level, observational cohort study of paediatric hospital admissions due to invasive pneumococcal disease (IPD) and diseases commonly caused by S. pneumoniae; all-cause otitis media (OM), pneumonia, sepsis and meningitis
Based on the eligibility criteria of the PHiD-CV programme, birth-cohorts 2005–2010 were grouped as vaccine non-eligible cohorts (VNEC) and birth-cohorts 2011–2015 as vaccine eligible cohorts (VEC)

Summary

Introduction

Methods: The 2005–2015 birth-cohorts were followed until three years of age and hospitalisations were recorded for invasive pneumococcal disease (IPD), meningitis, sepsis, pneumonia and otitis media. Hospital admissions for culture-confirmed IPD decreased by 93% (HR 0.07, 95%CI:0.01–0.50) and no hospitalisations for IPD with vaccine-type pneumococci were observed in the VEC. Worldwide mortality in children under five years of age from acute lower respiratory tract infections (LRTI) is estimated to be 105 per 100,000 children. Before a pneumococcal conjugate vaccine (PCV) was introduced into national immunization programmes, the rate of hospitalisations for pneumonia of children younger than two years of age was 293, 615 and up to 1274 per 100,000 children in Scotland [2], Sweden [3] and USA [4]. Other clinical presentations of pneumococcal infections, such as otitis media (OM) are more common and less severe

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