Real-world evidence on adherence and completion of the two-dose recombinant zoster vaccine and associated factors in U.S. adults, 2017-2021.

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.

Hepatitis vaccination adherence and completion rates and factors associated with low compliance: A claims-based analysis of U.S. adults.

Poor compliance with multi-dose vaccine schedules by adults for whom hepatitis (Hep) A and B vaccines are recommended contributes to major Hep A and B disease burdens among high-risk U.S. adults. Evidence on hepatitis vaccine series adherence, completion, timeliness of completion, and factors associated with these outcomes, is limited and not readily generalizable for U.S. adults. This retrospective, observational study examined adherence, completion, its timeliness, and the impact of sociodemographic and clinical factors on these outcomes among a large, geographically representative sample of U.S. adults. We analyzed the Optum Clinformatics SES administrative claims database (1/1/2010-6/30/2020) for recipients of 2-dose (HepA, HepB2) or 3-dose (HepB3, HepAB) hepatitis vaccines. Adherence was defined as receipt of booster doses within specified assessment periods, per label-recommended schedules. Completion (receipt of all doses) was assessed at 6, 12, 18, and 24 months.The study included 356,828 adults ≥19 years old who were continuously enrolled in a medical benefit plan for one (HepB2), six (HepB3; HepAB), or 18 months (HepA) prior to and following the index date (first observed vaccine dose). Adherence and 24-month completion rates were: HepA (27.0%, 28.4%), HepB2 (32.2%, 44.8%), HepB3 (14.3%, 37.3%), HepAB, (15.3%, 33.8%). Kaplan-Meier completion curves plateaued after about 6 months for HepB2 and about 12 months for HepA, HepB3, and HepAB vaccines. Logistic regression analyses showed risk for low adherence/completion was generally associated with male gender, younger age, Black or Hispanic race/ethnicity, lower educational or household income attainment, and more comorbidities. Adherence and completion rates for all hepatitis vaccine series are low, especially for males, younger adults, those with lower socio-economic status and more comorbidities. To our knowledge, this is the largest claims-based analysis of adherence and completion rates for U.S. adults initiating all currently available HepA and HepB vaccines. Findings may inform hepatitis vaccination programming.