Optimal gender-specific age for cost-effective vaccination with adjuvanted herpes zoster subunit vaccine in Chinese adults.

Abstract

BackgroundAdjuvanted herpes zoster (HZ) subunit (HZ/su) vaccine is recommended for healthy adults aged ≥50 years, yet vaccine efficacy is expected to wane over time. Age-sex specific cost-effectiveness analyses of HZ/su vaccine are warranted to inform decision-making on vaccine policy. We aimed to determine the optimal gender-specific age for cost-effective HZ/su vaccination in Hong Kong.MethodsA Markov model was used to compare outcomes with and without HZ/su in healthy males and females at age 50-80 years. Model outcome measures were total cost, HZ cases, and HZ-associated quality-adjusted life-years (QALYs) loss. Incremental cost per QALY saved (ICER) by HZ/su was estimated for each age-sex group. Sensitivity analyses were performed to examine robustness of model results.ResultsHZ/su reduced incidence of HZ in both males and females aged 50-80 years and the numbers needed to vaccinate to avoid one HZ case were lowest at age 60 years for males (6.05) and females (5.50). The highest QALY-saved occurred in females (0.00396 QALYs) and males (0.00379 QALYs) who were vaccinated at 60 years old. The ICERs were lowest at age 60-70 years for both genders. Using 1× gross domestic product per capita of Hong Kong (USD46,153) as willingness-to-pay threshold, HZ/su vaccine was accepted to be cost-effective for all female and male age groups at vaccine cost = USD160, for female aged 50-79 years and male aged 54-74 years at vaccine cost = USD200, and for female aged 59-71 years at vaccine cost = USD240.ConclusionsHZ/su vaccine is more likely to be cost-effective for males and females aged between 60-70 years than the extreme age groups (less than 60 years and older than 70 years) in Hong Kong. The age range for cost-effective acceptance of HZ/su vaccine appears to be broader in females than males given the same vaccine cost and willingness-to-pay threshold.