With population aging and the rising burden of chronic diseases, pneumococcal disease imposes increasing pressure on the healthcare system in China. This study evaluated the cost-effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in adults aged 50 years.

A decision-tree–based static cohort Markov model was developed to estimate lifetime costs and health outcomes from a societal perspective under a hypothetical strategy of PPSV23 vaccination at age 50 with revaccination at age 65 to assess long-term protection under waning immunity; a single-dose strategy was examined in scenario analyses. The model estimated quality-adjusted life-years, life-years, incremental cost-effectiveness ratios, and cases and deaths averted. Deterministic and probabilistic sensitivity analyses were conducted to assess parameter uncertainty. Price simulations were performed across different willingness-to-pay thresholds. Safety was evaluated using the Vaccine Adverse Event Reporting System through descriptive analysis and empirical Bayesian data mining.

The estimated incremental cost-effectiveness ratios for PPSV23 compared to no vaccination are ＄12,937.07 per quality-adjusted life-year gained and ＄9,622.25 per life-year gained, with the administration of PPSV23 preventing 1,115 cases and 35 deaths from a study population of 100,000 individuals. The greatest sensitivity was observed to variations in the discount rate, serotype coverage of PPSV23, vaccine efficacy of PPSV23 and cost per dose of PPSV23. No new or unexpected safety concerns for PPSV23 were identified.

PPSV23 is a cost-effective option for adults aged 50 years in China at higher willingness-to-pay thresholds (e.g., 2–3 × the gross domestic product per capita), with a favorable post-marketing safety profile.