Non-vaccine serotype pneumococcal carriage in healthy infants in South Africa following introduction of the 13-valent pneumococcal conjugate vaccine.

Background: Pneumococcal carriage studies provide a baseline for measuring the impact of pneumococcal conjugate vaccines (PCVs). The advent of conjugate vaccines has led to reductions in vaccine serotypes (VTs) in pneumococcal carriage. However, increasing non-vaccine serotypes (NVTs) remain a significant concern, necessitating continued surveillance of serotypes in the 13-valent PCV vaccine (PCV13) era.