Abstract
OBJECTIVE: Two vaccines against herpes zoster (HZ) are currently authorized for use in China: the adjuvanted recombinant zoster vaccine (RZV) and live-attenuated Zoster Vaccine Live (ZVL). The significant disparities in prices and efficacy between the two vaccines necessitate an evaluation of their relative value in order to make an informed choice. This study aimed to evaluate the comparative cost effectiveness of RZV, ZVL, and no vaccination for older adults at different ages from the societal perspective. METHODS: The Markov decision model was parameterized using vaccine efficacy data, the latest incidence rates, costs, and health-related quality-of-life data. Participants consisted of a cohort comprising adults aged ≥ 50 years in China. The lifetime health impacts, cost, life-year (LY), quality-adjusted life-year (QALY) gained and the incremental cost-effectiveness ratio (ICER), net monetary benefits (NMB), net health benefits (NHB), and expected value of perfect information (EVPI) were calculated. Sensitivity analyses, scenario analyses, and subgroup analyses were performed. RESULTS: Compared with no vaccination, RZV and ZVL could avoid 2,009,292 versus 510,192 HZ cases, and 334,637 versus 90,996 post-herpetic neuralgia (PHN) cases in the overall cohort, respectively. RZV and ZVL were more costly by US$1624 million versus US$896 million compared with no vaccination, with an additional 58,180 versus 23,390 QALYs. At threefold gross domestic product per capita, RZV had cost-effectiveness probabilities of 47.37% for ages 50-59 years, 83.24% for ages 60-69 years, 28.28% for ages 70-79 years, and 51.93% for ages ≥ 80 years, while ZVL had 7.07%, 12.79%, 69.55%, 2.82% probability, and no vaccination had 45.56%, 3.97%, 2.17%, 45.25% probability of being cost effective for the corresponding age cohorts. CONCLUSIONS: The strategy utilizing RZV demonstrated superior efficacy in reducing the burden of HZ compared with ZVL. RZV was most cost effective in the 50-59, 60-69 and ≥ 80 years age groups, and ZVL was most cost effective in the 70-79 years group.