Epidemiological, immunological and virulence characteristics of persistent Streptococcus pneumoniae vaccine serotypes following vaccine introduction

Abstract

Streptococcus pneumoniae vaccine serotypes can persist despite pneumococcal conjugate vaccine (PCV) introduction. To examine serotype persistence, we leverage 6,545 nasopharyngeal swabs collected from children hospitalised with pneumonia before and after PCV13 introduction in Mongolia. DNA microarray was used to identify changes in lineage composition within serotypes 6A, 6B, 14, 19F and 23F over the six-year surveillance period. Children carrying post-PCV lineages are less likely to have severe pneumonia (serotypes 6B, 14 and 19F) and be multi-drug resistant (serotypes 6A, 6B and 23F) than pre-PCV lineages. Of note, the post-PCV lineage of serotype 6B has lower antibody binding to capsule a..