Pneumococcal vaccine uptake and vaccine effectiveness in older adults with invasive pneumococcal disease in Germany: A retrospective cohort study

Background: Invasive pneumococcal disease (IPD) in people >60 years old is on the rise in Germany. There has been a recommendation for pneumococcal vaccination in this age group since 1998. Methods: We determined the vaccination status of people >60 years old with IPD in Germany. We assessed vaccine effectiveness (VE) of the recommended 23-valent polysaccharide vaccine (PPV23) against IPD using the indirect cohort method. Results: The rate of pneumococcal vaccination in older adults with IPD is low, 26%, with only 16% of people receiving a pneumococcal vaccine within five years of the IPD episode. Age-and gender-adjusted vaccine effectiveness (VE) for PPV23 was 37% (95% confidence interval 12% -55%). For people vaccinated with PPV23 less than two years prior to IPD, VE was-20% (-131% -34%), between two and four years prior to IPD, VE was 56% (20% -76%), and 47% (17% -63%) for those vaccinated >5 five years ago. Excluding serotype 3, overall VE for the remaining serotypes in PPV23 was 63% (49% -74%). For people receiving PPV23 within the past two years, VE against all serotypes except 3 was 49% (12% -71%); for people vaccinated between two and four years prior to IPD 66% (37% -82%); for those vaccinated >five years ago, 69% (50% -81%). VE of PPV23 against serotype 3 IPD only was-110% (-198% --47%). Conclusions: To reduce IPD in older adults in Germany, we must increase the rate of pneumococcal vaccine uptake. For 22/23 serotypes, PPV23 was effective. Serotype 3 remains a major problem. Funding: This work was supported by an investigator-initiated research grant from Pfizer. (C) 2021 The Authors. Published by Elsevier Ltd.