A Cost-Effectiveness Analysis of PCV21 Use in Vaccine-Experienced Adults Aged ≥65 Years in the U.S

In the U.S., pneumococcal conjugate vaccine (PCV) with higher valency such as 21-valent pneumococcal conjugate vaccine (PCV21) is recommended for adults aged ≥65 years who have previously received pneumococcal vaccines (referred to as vaccine experienced). This study assessed the cost-effectiveness of PCV21 versus 23-valent pneumococcal polysaccharide vaccine (PPSV23), 15-valent pneumococcal conjugate vaccine (PCV15), and 20-valent pneumococcal conjugate vaccine (PCV20) in adults aged ≥65 years who were previously vaccinated 5 years ago with PPSV23 or PCV13 or 2 years ago with PCV15.

A published multicohort Markov model was used to estimate the lifetime clinical and economic outcomes of each vaccination strategy from a societal perspective. Quality-adjusted life years and costs (in 2023 U.S. dollars) were discounted at a 3% annual rate. Sensitivity and scenario analyses were conducted to identify influential variables.

Compared with PPSV23, PCV21 in PCV13-, and PCV15-experienced adults would cost $130,700 and $173,700 per quality-adjusted life year gained, respectively. Administering PCV21 in PPSV23-experienced adults would cost $2,700 per QALY gained compared with administering PCV15. PCV21 would be cost saving compared with PCV20 in all vaccine-experienced adults. Discount rates and vaccine effectiveness were the most influential inputs, and the quantitative results were robust in probabilistic sensitivity analyses. When vaccine history was extended to 8 (instead of 5) years for the PPSV23-, PCV13-, or PPSV23+PCV13-experienced adults , PCV21 were slightly more favorable in most comparisons.

In the U.S., a dose of PCV21 in adults aged ≥65 years who have previously received a pneumococcal vaccine has the potential to prevent a considerable number of pneumococcal disease cases and deaths while remaining economically reasonable over a wide range of inputs and scenarios.