Persistence of Vaccine Serotypes in IPD following implementation of PCV13.

Vaccine-type cases of IPD in children under six with a known vaccination status, who received either only PCV13 or no vaccine at all are shown. No IPD cases from serotypes 5, 23F, or 4 occurred during the PCV13 period (2009–2010 through 2014–2015). One case of serotype 18C IPD occurred in the 2010–2011 season, and one case of serotype 9V IPD occurred in the 2011–2012 season, both of which were in unvaccinated children.