In the United States, Zoster Vaccine Live (ZVL) has been on the market since 2008, while a non-live adjuvanted Recombinant Zoster Vaccine (RZV) was authorized in 2017. According to the literature, declining ZVL effectiveness may need further immunization. The Advisory Committee on Immunization Practices advised RZV immunization in immunocompetent individuals aged 50 and older, including those who had previously had the ZVL vaccine. The goal of this study was to assess the cost-effectiveness of vaccinating previously immunized US individuals aged 60 and up against ZVL. The ZOster ecoNomic Analysis (ZONA) model, a deterministic Markov model, was modified to track a hypothetical 1 million(M)-person cohort of ZVL-vaccinated individuals in the United States. Costs and quality-adjusted life-years (QALYs) were given for the cohort over the course of their lives beginning with the year of extra immunization and discounted by 3% yearly. The model projected that RZV vaccination 5 years following ZVL vaccination will lower disease burden relative to no further immunization, resulting in a gain of 1,633 QALYs at a total societal cost of $96M.

Compared to revaccinating with ZVL, RZV vaccination would result in a gain of 1,187 QALYs and a societal cost reduction of about $84 million. These findings’ robustness was confirmed by sensitivity, scenario, and threshold studies. Immunization with RZV is expected to be cost-effective compared to no extra vaccination, assuming a $100,000/QALY threshold, and cost-saving compared to ZVL revaccination of US people aged 60+ who have previously been vaccinated with ZVL.