PIH31 - Revisiting The Cost-Effectiveness Of Herpes Zoster Vaccination In Elderly People In The United States

Abstract

Herpes Zoster (HZ) or shingles, common among elderly people, increases with age and so does its severe outcomes including post herpetic neuralgia (PHN). Although efficacious in immunocompetent adults aged ≥ 50 years, protection from a licensed vaccine decreases in time which, faced with increasing disease risks, makes age of vaccination crucial. To evaluate the cost effectiveness of HZ vaccination among adults aged ≥50 years and identify the public health and economically optimal vaccination age. We used a cohort-based decision analysis model to compare the age-specific incidence, health care resource utilization, costs and quality-adjusted life years (QALYs) related to HZ, PHN and non-pain complications among unvaccinated and vaccinated individuals at either age 50, 60 or 70 years. Health outcomes, resource utilization and costs were projected for the US cohorts from 50 to 99 years of age. It incorporates HZ-specific QALY scores for duration and intensity of pain and the probabilities for Monte Carlo simulations. QALYs gained and cost per QALY gained from vaccination are the primary estimates. Sensitivity analyses were conducted on vaccine efficacy duration and other variables. Vaccinating at age 60 would prevent more shingles cases (26,147 cases per million persons) followed by vaccinating at age 70 while vaccinating at age 50 prevents the less number of shingles cases (21,269 vs. 19,795 respectively). However, vaccinating at age 70 would be the strategy with the biggest impact (8,055 PHN cases prevented), followed by age 60 and then age 50 (4,055 vs. 1,012 PHN cases prevented, respectively). Vaccinating at age 70, 60, and 50 would societally cost $38,000, $80,000 and $272,000 per QALY saved, respectively. Overall, the optimal age for vaccination would be at 70 years. While various uncertainties remain, our results were robust based on the sensitivity analyses and the magnitude of the differences in outcomes and costs between strategies.