Impact of CRM197-based conjugate vaccines, schedules, and regions on pneumococcal immunogenicity in young children: systematic review

Abstract

Population-level introduction of pneumococcal conjugate vaccines (PCVs) has increased non-vaccine serotype invasive pneumococcal disease (IPD) incidence in children. Higher-valency PCVs were developed to address shifting disease-causing serotypes. This systematic review and meta-analysis defines trends in CRM197-based PCV immunogenicity in children 95% for all serotypes except 3. IgG responses increased with primary-dose number, and were further enhanced by a booster, although magnitude varied by serotype and vaccine; for PCV20, IgG GMCs after two-primary doses were still below the 0.35 µg/mL threshold for six serotypes. A general downward trend in IgG GMCs was observed with increasing vacci..