The potential impact of increased recombinant zoster vaccine coverage on the burden of herpes zoster among adults aged 50-59 years

Abstract

Introduction: Recombinant zoster vaccine (RZV) is recommended in the US for prevention of herpes zoster (HZ) in adults aged ≥50 years. Vaccination rates remain suboptimal for adults 50-59 years compared with adults ≥50 years overall. The objective of this study was to model changes in outcomes associated with improved RZV vaccination coverage in US adults 50-59 years.

Methods: A multicohort Markov model compared a scenario using real-world vaccination coverage for US adults 50-59 years in 2020 versus scenarios assuming higher coverage. Outcomes, based on a lifetime horizon, included HZ cases and complications avoided, quality-adjusted life-years (QALY), and costs. Model inputs included HZ epidemiology, RZV vaccine efficacy, coverage, adverse events, and costs, based on published literature and US sources. Some inputs were updated from previous models, including real-world estimates of RZV coverage, series completion, and reflecting longer-term data on waning of vaccine efficacy. The model utilized a cohort size of 42,756,488 individuals based on the 2020 US population census.

Results: The model projected that increasing RZV coverage in adults 50-59 years from 7.3 % to 14.6 % (to coverage for adults 60-64 years in 2020) would avoid an additional 504,468 HZ cases, 42,077 postherpetic neuralgia cases, and 56,247 cases of other HZ-associated complications. The increase in vaccine coverage would result in higher vaccination-related costs of $1,172,411,566, but the avoided HZ cases and complications would be expected to result in direct cost savings of $721,973,386 and indirect cost savings of $593,497,480 from avoided productivity loss. Overall, a gain of 5,230 discounted QALYs and cost savings of $143,059,299 from a societal perspective would be realized.

Conclusion: Modestly higher RZV coverage in US adults 50-59 years could reduce the clinical burden associated with HZ and may result in societal cost savings. These findings demonstrate the potential value of increasing RZV vaccination in this population.

Keywords: Adult vaccination; Cost savings; Herpes zoster; Recombinant zoster vaccine; Vaccination rate; Vaccine coverage.