Cost-effectiveness of the Adjuvanted Herpes Zoster Subunit Vaccine in Older Adults.

Importance: The live attenuated herpes zoster vaccine (ZVL) is recommended for immunocompetent adults 60 years or older, but the efficacy wanes with age and over time. A new adjuvanted herpes zoster subunit vaccine (HZ/su) has higher efficacy but might be more expensive. The choice of vaccines depends on their relative values. Objective: To assess the cost-effectiveness of HZ/su. Design, Setting, and Participants: Markov decision model with transition probabilities based on the US medical literature. Participants were immunocompetent adults 60 years or older. Data were derived from participant groups ranging in number from less than 100 to more than 30 000 depending on the variable assessed. The study dates were July 1 to 31, 2017. Exposures: No vaccination, ZVL (single dose), and HZ/su (2-dose series) vaccine administered at different ages. Main Outcomes and Measures: Total costs and quality-adjusted life-years (QALYs) were estimated.
Results: Based on randomized clinical trial data, at a price of $280 per series ($140 per dose), HZ/su was more effective and less expensive than ZVL at all ages. The incremental cost-effectiveness ratios compared with no vaccination ranged from $20 038 to $30 084 per QALY, depending on vaccination age. The finding was insensitive to variations in most model inputs other than the vaccine price and certain combinations of low adherence rate with a second dose and low efficacy of a single dose of HZ/su. At the current ZVL price ($213 per dose), HZ/su had lower overall costs than ZVL up to a price of $350 per 2-dose series. In probabilistic sensitivity analysis, HZ/su had 73% probability of being cost-effective for 60-year-olds at $50 000 per QALY. Conclusions and Relevance: Under conservative assumptions, at a price of $280 per series ($140 per dose), HZ/su would cost less than ZVL and has a high probability of offering good value.