Changes in Pneumococcal and Hexavalent Vaccination Schedule in Term-Born Infants: Potential Impact on Preterm Infants

OBJECTIVES: Initially, the vaccination schedule for hexavalent (HEXA) and pneumococcal-conjugate-vaccines (PCV) in infants in Germany followed a 3+1-schedule (2, 3, 4, 11-14 months). The German Standing Committee on Vaccination (STIKO) changed this schedule for term infants (TI) to a 2+1-schedule (2, 4, 11 months) for PCV and HEXA in August 2015 and 2020, respectively. Preterm infants (PI) remained on the 3+1-schedule for both vaccines.

This study aims at assessing the potential impact of these changes in the TI vaccination schedule on the vaccination behavior in PIs.

METHODS: We conducted a retrospective claims data analysis using the InGef Research Database (age- and gender-representative sample of the statutory health insured German population). The study population consisted of all infants born in 2013, 2016, 2018, or 2020 with an individual follow-up of 24 months. PIs were identified by ICD-10-GM codes P07.2 and P07.3. We assessed vaccination rates of full vaccination series (FVR) in PIs before and after changes in STIKO recommendation for TIs, in comparison to the respective FVR in TIs.

RESULTS: With a common 3+1-PCV-schedule for TIs and PIs in 2013, the FVRs were similar at 65.4% and 68.3%. After the change to a 2+1-schedule for TIs, the FVR increased to 75.6% (76.7%, 78.5%) for TIs, while it decreased significantly to 40.8% (46.8%, 52.5%) for PIs in 2016 (2018, 2020). With a common 3+1-HEXA-schedule for TIs and PIs in 2013 (2016, 2018), the FVRs were similar at 69.1% (72.9%, 73.8%) and 66.3% (68.7%, 71.0%), respectively. After the change to a 2+1-schedule for TIs in 2020, the FVR increased to 81.4% for TIs, while it decreased significantly to 57.8% for PIs.

CONCLUSIONS: Despite the constant 3+1-recommendation, a decrease in FVR in PIs could be observed when the schedule for TIs changed. More effort is needed to protect the vulnerable group of PIs.