Analysis of health claims data on vaccination coverage in older adults in Bavaria, Germany: Influenza, pneumococcus and herpes zoster

Background: Vaccination is essential, especially in older adults whose immune system function declines with age. The COVID-19 pandemic and its associated lockdowns temporarily disrupted routine vaccination services. We aimed to assess vaccination coverage for Influenza, Pneumococcus, and Herpes zoster among older adults in Bavaria over time and investigate potential pandemic effects on these rates. Methods: Based on health claims data from the Bavarian Association of Statutory Health Insurance Physicians (KVB), we estimated the percentage of adults aged 60 years and older vaccinated following the German Standing Committee on Vaccinations (STIKO) recommendation for Influenza (2012−2021), Pneumococcus (2017–2021) and Herpes zoster (2019–2021), stratified by sex and 10-year age groups. Using time series regression analysis, we estimated the effect of the pandemic period (2020−2021) on quarterly Influenza and Pneumococcal vaccination rates. Results: In the first year of the pandemic (2020), Influenza, Pneumococcus and Herpes zoster coverage in both sexes increased by 9.9, 8.7, and 2.5 percentage points (pp), respectively. In 2021, Influenza coverage decreased by 4.7 pp., while Pneumococcus and Herpes zoster coverage increased by 2.7 and 3.8 pp., respectively. Influenza and Pneumococcal vaccinations showed a seasonal pattern, with vaccinations occurring mainly in the fourth quarter; this pattern was distorted for Pneumococcus during the pandemic. Per the time series regression analysis, Influenza vaccination rates in the fourth quarters of 2020 and 2021 were 7.86 (95 %CI: 5.10–10.62) and 8.87 (95 %CI: 5.80–11.54) pp. higher for males and females, respectively, compared to that of the pre-pandemic period. During the pandemic, the quarterly Pneumococcal vaccination rates increased by 0.68 (95 %CI: 0.19–1.18) pp. in males and 0.80 (95 %CI: 0.30–1.30) pp. in females. Conclusion: The heightened increase in vaccination rates observed in 2020 may have resulted from increased vaccination awareness during the pandemic. As the pandemic effect wanes, more efforts are needed to sustain and increase these vaccination rates.