Invasive pneumococcal disease in children under 16 years of age: Incomplete rebound in incidence after the maximum effect of PCV13 in 2012/13 in Germany

Objective: To identify a potential nadir of the impact of pneumococcal conjugate vaccination (PCV) in infancy on invasive pneumococcal diseases (IPD) in children under 16 in Germany. Methods: Active surveillance on IPD based on two independent data sources with capture-recapture correction for underreporting. Annual incidence rates by age group, serotypes, site of infection, and relative incidence reduction compared to pre-vaccination period (1997-2001) at nadir and for the most recent season are reported. We calculated vaccine coverage at the age of 24 months using health insurance claims data. Results: 96-97% of children had received at least two doses of PCV since 2009. The maximum impact on overall IPD incidence was achieved in 2012/13 (-48% [95% Cl: -55%; -39%]) with a rebound to -26% [95% CI: -36%; -16%] in 2015/16. Non-PCV13 serotypes accounted for 84.1% of the IPD cases in 2015/16. The most frequent non-PCV serotypes in IPD in 2014/15 and 2015/16 were 10A, 24F, 15C, 12F, 38, 22F, 23B, and 15B. The impact at nadir was highest in children 0-1 years of age both in meningitis and non-meningitis cases, whereas the impact for other age groups was higher for meningitis cases. The rebound mainly pertained to non-meningitis cases. Conclusion: The maximum impact of pneumococcal conjugate vaccination has been attained and signs of a rebound are apparent. Sustained surveillance for IPD in children is warranted to assess whether these trends will continue. There may be a need for vaccines using antigens common to all serotypes. (C) 2017 Elsevier Ltd. All rights reserved.