Prevention of pneumococcal infections in childhood: two decades of progress.

Abstract

This review highlights progress in combating pediatric pneumococcal disease in the era of pneumococcal conjugate vaccines (PCVs). This review is timely given the development of increased valency PCVs for potential use in children. Countries implementing vaccination programs with PCVs have witnessed dramatic reductions in cases of childhood invasive pneumococcal disease (IPD). In the US, the largest decline of IPD followed the introduction of 7-valent PCV with additional decreases following the switch to 13-valent PCV (PCV13). Despite these gains, IPD still occurs in the US but at much lower rates. Likewise, pneumonia hospitalizations and office visits for otitis media have decreased. Nasopharyngeal colonization with pneumococci has persisted due to replacement by nonvaccine serotypes: colonizing non-PCV13 serotypes have less invasive potential. The PCV era has also been marked by reductions in the proportions of pneumococcus showing nonsusceptibility or resistance to some antimicrobial agents. Furthermore, PCVs have an excellent safety profile. Despite proven safety and efficacy, childhood vaccination programs in some countries do not include PCVs, resulting in the majority of global deaths attributable to pneumococcus. Increased worldwide vaccination of children and the development of higher valency vaccines holds additional promise for further reductions in childhood IPD.