Evaluating pneumococcal vaccine strategies in older adults in Germany: proficiency and cost-utility

<bold>Background:</bold> Recently, the German standing vaccination committee (STIKO) recommended the use of a 20-valent pneumococcal conjugate vaccine (PCV20) in older adults to reduce the burden of pneumococcal diseases (PD). This study assesses the performance and cost-utility of PCV20 in comparison with other pneumococcal vaccines (PCV15 and PPSV23) in adults ≥ 60 years old in Germany. <bold>Methods:</bold> A dynamic transmission model of pneumococcal carriage integrating eight competing groups of serotypes was formulated to analyze the impact of childhood vaccination on the epidemiology of PDs in older adults, considering serotype replacement and herd effects. Three infant vaccination scenarios were evaluated: (1) continuation of PCV13, (2) adopting PCV15 over PCV13 (January 2024) and (3) adopting PCV20 over PCV13 (January 2024). <bold>Results:</bold> Compared with no vaccination, 5048, 6312, and 13786 hospitalizations were prevented by PPSV23, PCV15, and PCV20 vaccination of the elderly in scenario (1). In scenario (2), prevented hospitalization amounted to 4372, 3874, and 11410 for PPSV23, PSCV15, and PCV20. PPSV23 vaccination decreased hospitalizations by 2792, PCV15 by 4613, and PCV20 by 5367 in scenario (3). ICERs of PCV20 compared to PPSV23 were 7771 Euro/QALY in scenario (1), 10536 Euro/QALY in scenario (2), and 32271 Euro/QALY in scenario (3). <bold>Conclusion:</bold> Our analysis concluded that vaccinating elderly with PCV20 is preferable to PCV15 or PPSV23 from economic and epidemiological perspectives. However, results for scenarios (2) and (3) must be interpreted with extreme caution due to incomplete epidemiological data.