Vaccination rates and adherence in premature infants before and after pneumococcal conjugate vaccine schedule change for term infants - A claims database analysis in Germany

Abstract

Background: In 2015, the German Standing Committee on Vaccination (STIKO) changed the pneumococcal conjugate vaccination (PCV) schedule for mature infants from a 3+1scheme (2, 3, 4, and 11-14 months of age) to a 2+1scheme (2, 4, and 11-14 months of age). For premature infants, the 3+1scheme remained. The aim of this study was to assess vaccination rates, completeness, and timeliness for PCV in premature infants before and after the modified recommendation.

Methods: A retrospective claims data analysis using the "Institut für angewandte Gesundheitsforschung Berlin" Research Database was conducted. Premature infants born in 2013 and 2016 with an individual follow-up of 24 months were included. Hexavalent combination (HEXA) vaccination with a consistent 3+1recommendation for mature and premature infants was analyzed as reference vaccination.

Results: After 24 months, the PCV rate for at least one dose remained stable in premature newborns of 2016 compared to 2013, while the HEXA vaccination rate increased slightly. However, a significant decrease of a completed PCV schedule (4 doses) in premature infants was noted, whereas the completeness of HEXA vaccination did not change. The timeliness of PCV in premature newborns increased for the first and the booster PCV, while the timeliness of HEXA immunization did not change from 2013 to 2016.

Conclusion: Although STIKO still recommends a 3+1PCV schedule for premature infants in Germany, premature infants were vaccinated according to the changed recommendations for mature born infants. A substantial share of premature infants remained unvaccinated, and their vaccinations were often delayed.

Keywords: Claims data analysis; Hexavalent vaccination; Pneumococcal conjugate vaccine; Premature newborns; Vaccination rates.