Evaluation of the association of pneumococcal conjugate vaccine immunization and density of nasopharyngeal bacterial colonization using a multiplex quantitative polymerase chain reaction assay

The reduction in PCV7-serotype colonization impacted on colonization prevalence and density of other bacterial species of the nasopharynx. The clinical relevance of this needs further exploration in relation to mucosal and invasive disease outcomes, as well as for higher valency PCV vaccines.