Long-term impact of pneumococcal polysaccharide vaccination on nasopharyngeal carriage in children previously vaccinated with various pneumococcal conjugate vaccine regimes

摘要: Previously, the Fiji Pneumococcal Project (FiPP) evaluated reduced dose immunization schedules that incorporated pneumococcal protein conjugate and/or polysaccharide vaccine (PCV7 and 23vPPV, respectively). Immune hyporesponsiveness was observed in children vaccinated with 23vPPV at 12 months of age compared who did not receive 23vPPV. Here we assess long-term impact vaccination on nasopharyngeal carriage rates densities Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus Moraxella catarrhalis. Nasopharyngeal swabs (n = 194) were obtained from healthy participated FiPP (now aged 5–7 years). S. pneumoniae isolated identified by standard culture-based methods, serotyped using latex agglutination Quellung reaction. Carriage H. M. catarrhalis determined real-time quantitative PCR. There no differences rate or density influenzae PCV7 participants overall. However, between two main ethnic groups: Fijian Indian descent (Indo-Fijian) less likely to carry catarrhalis, there evidence a higher indigenous (iTaukei) children. Polysaccharide appeared have effects varied groups, associated iTaukei children, while lower Indo-Fijian Overall, had carriage, but may impacted varying suggesting current WHO schedule recommendations against use under years are appropriate.