Flowchart of IPD cases included in regression analysis.

At the top, all cases of IPD in Germany occurring in children between 90 days and 6 years of age, born after the start of the study period, July 1, 2007 to June 30, 2015, fit the study criteria (n = 602). Depending on vaccination status, year of infection, and age of child, cases were grouped for analysis into a PCV7 group (n = 244), a PCV10 group (n = 149), and a PCV13 group (n = 374). Also shown are all IPD cases from children in each of the respective groups, and vaccine-type IPD cases from children in each group.