Emerging Streptococcus pneumoniae Strains Colonizing the Nasopharynx in Children After 13-valent Pneumococcal Conjugate Vaccination in Comparison to the 7-valent Era, 2006–2015

Abstract

Serotypes 35B, 23B, 21 and 15A/B/C rapidly emerged as NP colonizers in the early PCV13 era. Genetically divergent strains with ST558 and ST62 emerged. Resistance to common antibiotics declined after the introduction of PCV13.