Cost-effectiveness of the 20-valent pneumococcal conjugate vaccine versus the 23-valent pneumococcal polysaccharide vaccine for older adults in South Korea

Background: Despite the demonstrated immunogenicity and safety of the 20-valent pneumococcal conjugate vaccine (PCV20) in older adults, the cost-effectiveness of the PCV20 was not examined compared to the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in South Korea. Therefore, this study aimed to evaluate the cost-effectiveness of PCV20 compared with PPSV23 in adults aged 65 years and older in South Korea. Methods: We constructed a Markov model that included susceptible states, invasive pneumococcal disease (IPD), non-bacteremic pneumonia (NBP), and death. The population was categorized by disease risk status (low risk, moderate risk, and high risk) and age group (65–74/75–84/85–99 years) at model entry. The annual incidence and mortality of IPD and NBP associated with PCV20 and PPSV23 were estimated based on serotype coverage, vaccine coverage, and vaccine effectiveness. The disease costs and utilities were obtained from previous studies. The incremental cost-effectiveness ratio (ICER) was used to evaluate cost-effectiveness within the threshold of 16,824 USD per quality-adjusted life-year (QALY). Results: Among the total population (n = 8,843,072), PCV20 prevented 1941 and 50,575 cases of IPDs and NBPs, respectively, and 898 and 8593 deaths due to IPDs and NBPs compared to PPSV23. The total medical cost per person was 12.11 USD higher in PCV20, with a gain of 0.0053 LYs and 0.0045 QALYs per person. The ICER for PCV20 and PPSV23 was 2270 USD/LY and 2677 USD/QALY. Conclusions: In South Korea, PCV20 is a cost-effective option compared with PPSV23 for adults aged 65 years and older. These cost-effectiveness results provide evidence for decision-making regarding the approval and National Immunization Program implementation of PCV20.