Cost Effectiveness of a Shingles Vaccine Booster for Currently Vaccinated Adults in the US

Introduction: The Advisory Committee on Immunization Practices recommends a single dose of the live attenuated herpes zoster vaccine in people aged >= 60 years. Because vaccine-induced protection decreases to zero after 10 years, many vaccinated people will soon be subject to an increased risk of the disease. The study objective was to determine the cost effectiveness of a herpes zoster vaccine booster and its optimal timing among immunocompetent adults first vaccinated at aged >= 60 years. Methods: A Markov model was built to follow vaccinated individuals for a lifetime. From the societal perspective, costs and quality-adjusted life years were compared between no booster versus booster options. A booster was given any time between 1 and 20 years after the first dose, and for those who had the first dose at different ages: 60, 70, and 80 years. Because people entered the model already vaccinated, costs and side effects of the first dose were not included. The booster was assumed to have the same efficacy and waning rate as the initial vaccination. Model inputs were based on published literature. A cost effectiveness threshold of $100,000/quality-adjusted life year was used. The analysis was conducted in 2016. Results: Cost effectiveness of a booster varied by age and time since vaccination. The booster cost <$100,000/quality-adjusted life year if given 45 years after the initial dose, but was most cost effective at around 10 years. The finding was robust to wide variations in model inputs. Conclusions: Under current assumptions, a booster dose of herpes zoster vaccine would be cost effective for all vaccinated people 10 years after initial vaccination. (C) 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.