Similar impact and replacement disease after pneumococcal conjugate vaccine introduction in hospitalised children with invasive pneumococcal disease in Europe and North America

Arto A Palmu,Philippe De Wals,Maija Toropainen,Shamez N Ladhani,Geneviève Deceuninck,Mirjam J Knol,Elisabeth A.M Sanders,Elizabeth Miller

doi:10.1016/j.vaccine.2021.01.070

Abstract

High incidence of childhood invasive pneumococcal disease (IPD) in the US declined steeply after 7-valent pneumococcal conjugate vaccine (PCV7) introduction, outweighing reductions observed elsewhere. We re-analysed aggregate published data and compared pre- and post-PCV IPD-incidence in different countries to explore PCV impact on hospitalised and outpatient IPD separately. The proportion of hospitalised IPD cases was consistently high (>80%) in England&Wales, Finland, the Netherlands, and Quebec/Canada, but only 32% in the US before PCV introduction, increasing to 69% during the PCV era. In the US, a higher reduction in outpatient IPD incidence (94% in 2015 versus 1998–99) was observed compared to hospitalised IPD (79%); a 51% reduction in the non-PCV13-type IPD incidence among outpatient cases was estimated compared to a >2-fold increase for hospitalised cases. After stratification by hospitalization status, PCV programmes resulted in similar impact and serotype replacement in hospitalised IPD in US when compared to other countries.

Highlights

The first pneumococcal conjugate vaccine against the seven most prevalent pneumococcal serotypes causing invasive disease in children (PCV7) was licensed in The United States in 2000 and in Europe in 2001
Before PCV introduction, only 32% of invasive pneumococcal disease (IPD) cases in children below 5 years were hospitalised in the US but this proportion increased to 69% after PCV introduction by 2012
67 to 99% of childhood IPD cases were hospitalised in the other countries and this proportion remained relatively constant over the surveillance period (Fig. 1, Supplement Figure 1)

Summary

Introduction

The first pneumococcal conjugate vaccine against the seven most prevalent pneumococcal serotypes causing invasive disease in children (PCV7) was licensed in The United States in 2000 and in Europe in 2001. Other countries have reported less remarkable reductions in IPD incidence, mostly because of more rapid emergence of IPD due to non-PCV serotypes as a result of the replacement phenomenon [2,3,4,5,7].

Methods

Results

Conclusion