Impact of Serotype Uncertainty on Adult Pneumococcal Vaccine Options: A Value of Information Analysis

Potential public health effects of adult pneumococcal vaccines are uncertain because of observed changes in pneumococcal serotype epidemiology. Prior analyses favored the 21-valent pneumococcal conjugate vaccine but observed that serotype changes in some populations could decrease its favorability. Value of information analysis could guide further research to clarify uncertainty.

Analyses evaluated value of information in U.S. cohorts aged 65 years, comparing adult pneumococcal vaccines. Model parameters included vaccine serotype-specific pneumococcal disease and mortality risks from U.S. data, vaccination rates from published literature, and vaccine effectiveness from clinical trials and Delphi panel estimates. Analyses estimated expected value of perfect information and expected value of partial perfect information at willingness-to-pay thresholds from $0 to $200,000 per quality-adjusted life year gained. A secondary analysis examined those aged 50-64 years. Data were collected and analyzed in 2024.

In those aged 65 years, value of information estimates were highest at the $100,000/quality-adjusted life year gained threshold and were markedly less at higher thresholds. At $100,000/quality-adjusted life year gained, population expected value of perfect information was $178.1 million; expected value of partial perfect information for pneumococcal disease mortality and disability parameters combined was $89.6 million and for vaccine effectiveness parameters was $73.8 million. The 21-valent pneumococcal conjugate vaccine serotype incidence expected value of partial perfect information was $19 million. In those aged 50-64 years, expected value of partial perfect information for vaccine effectiveness was $2.9 million and for 21-valent pneumococcal conjugate vaccine serotype incidence was $139,080.

Value of information results were more supportive of further research on selected parameters in those aged 65 years than in those aged 50 years. However, expected value of partial perfect information values for 21-valent pneumococcal conjugate vaccine serotype incidence was substantially lower in both age groups, supporting adult 21-valent pneumococcal conjugate vaccine use regardless of serotype uncertainty.