Trends in serotype prevalence in invasive pneumococcal disease before and after infant pneumococcal vaccination in Belgium, 2002–2010

Abstract Objectives We evaluated the effect of the infant 7-valent pneumococcal conjugate vaccine (PCV7) program on the serotype distribution in invasive pneumococcal disease in the Belgian population. Methods Serotyping was performed on 13,998 bacteraemic and pleural fluid isolates sent to the National Reference Laboratory between 2002 and 2010. We compared the distribution of serogroups (SGs) between the pre- (2002–2004) and post-PCV7 (2007–2010) era for children ( Results The proportion of cases caused by PCV7-SGs in subjects p p p p p Conclusions PCV7 has an impact on SG distribution of invasive pneumococcal disease isolates of vaccinated and unvaccinated subjects. SG replacement forms a major threat to the success of PCV7. PCV13, including several additional replacement serotypes (STs 1, 7F, 19A), represents an attractive alternative.