The study design and analysis controlled for influence of potentially confounding trends, such as improvement of day-care carriage and decreasing prevalence of smoking during the study period.
The study compares the incidence and serotype distribution of invasive pneumococcal disease (IPD) for pneumococcal meningitis and non-meningitis IPD in children from 2007 to 2010 with reference to the pre-vaccination period from 1997 to 2001 in Germany.
This study demonstrates that PCV13 is immunogenic and safe in children previously vaccinated with PCV7. By eliciting high antibacterial immune responses to the additional serotypes, PCV13 provides protection against these serotypes, which are important causes of pneumococcal disease globally.
The evidence presented in the article strongly supports the notion that serotype replacement has occurred in invasive pneumococcal disease in most populations and is caused by the vaccine.