Introduction: Poor compliance with adult vaccination recommendations contributes to substantial disease burden. Evidence on adherence, completion, and completion timeliness for the 2-dose recombinant herpes zoster vaccine (RZV) and factors associated with these outcomes is limited and not readily generalizable for the entire U.S.
Methods: This retrospective, observational study examined adherence, completion, and the impact of sociodemographic, clinical and geographical factors among U.S. adults ≥ 50 years receiving RZV (4/20/2017 to 3/31/2021), using a large, geographically representative administrative claims database. Continuous enrollment in a medical benefit plan for six months prior to and following the index date (first observed vaccine dose) was required. Adherence was defined as receipt of the 2nd dose within 2-6 months, per label recommendation. Completion (receipt of all doses) was assessed at 6, 12, 18, and 24 months.
Results: Among 726,352 adults included, the adherence rate was 71.8%. Among 208,311 adults with 24-month follow-up, the completion rate was 72.3% after 6 months and 86.2% after 24 months. Logistic regression showed low adherence/completion was associated with younger age, Black or Hispanic race/ethnicity, lower income, lower educational attainment, and possessing commercial rather than Medicare healthcare insurance. Recipients identified using pharmacy claims had much higher adherence (74.0%) than those identified using medical claims (48.0%).
Conclusions: Adherence and completion rates for RZV are suboptimal, especially for adults aged 50-64, racial/ethnic minorities, individuals with lower socio-economic status and those without Medicare insurance. More research and public health efforts are needed to understand and address potential barriers to RZV uptake, adherence and completion.
Keywords: Administrative claims data; U.S. adults; Vaccination disparities; Vaccine adherence; Vaccine dose-series completion; Zoster vaccines.
Copyright © 2022 Elsevier Ltd. All rights reserved.