Real-world effectiveness of adjuvanted RSVPreF3 vaccination in the prevention of RSV-related hospitalization among US adults aged ≥60 years.

Abstract

There is a growing body of evidence on the real-world effectiveness of adjuvanted respiratory syncytial virus (RSV) prefusion F3 (RSVPreF3) vaccination against RSV-related hospitalization among older adults. However, additional research is needed to further estimate vaccine effectiveness (VE) in subgroups at increased risk for severe RSV disease. What is the VE of adjuvanted RSVPreF3 vaccination against RSV-related hospitalization among adults aged ≥60 years in the United States (US), including subgroups at increased risk for severe RSV disease? This retrospective cohort study utilized claims data from the Optum Research Database (ORD). Adjuvanted RSVPreF3-vaccinated and unvaccinated adults aged ≥60 years were identified (August 2023-May 2024) and exact matched 1:4 by age, sex, insurance type, and US state. Vaccination date was assigned as the index date. Baseline characteristics were measured during the 12-month pre-index period, with continuous enrollment required, and were balanced using propensity score-based weighting. Individuals were followed from 14 days post-index to the earliest of: disenrollment, death, RSV vaccination, or end of the analysis period (May 31, 2024). Hazard ratios (HRs) were estimated using Cox proportional hazards regression, comparing risk of RSV-related hospitalization, with VE calculated as (1 - HR) x 100%. The study included 520,440 vaccinated and 2,081,760 unvaccinated individuals. Median follow-up was 5.6 months, with a maximum of 9.7 months. Estimated VE was 75.6% (95% confidence interval [CI]: 69.8-80.2%). VE estimates in key subgroups included 72.5% (64.3-78.8%) among those with chronic pulmonary disease, 72.2% (64.1-78.4%) among those with cardiovascular disease, 82.3% (74.2-87.9%) among those with diabetes, and 71.4% (57.0-81.1%) among those who were immunocompromised. These findings highlight the effectiveness of adjuvanted RSVPreF3 vaccination in preventing RSV-related hospitalization among older adults, including those at increased risk, suggesting that vaccination is an effective strategy in reducing RSV disease burden.