Public health impact and cost-effectiveness of adjuvanted RSVPreF3 vaccination among US adults aged 18–49 years at increased risk for severe RSV disease

BACKGROUND: Adults with certain medical conditions (e.g., chronic pulmonary or cardiovascular disease, weakened immune systems) are at increased risk for severe respiratory syncytial virus (RSV) disease, which can have substantial clinical and economic burden. This study evaluated the public health impact and cost-effectiveness of adjuvanted RSVPreF3 vaccination among United States (US) adults aged 18-49 years at increased risk for severe RSV disease. METHODS: A static, multicohort Markov model simulated adjuvanted RSVPreF3 vaccination versus no vaccination over 5 years, assuming the same uptake as influenza vaccines. The base-case population included adults aged 18-49 years with ≥1 of the following risk factors for severe RSV disease: asthma, coronary artery disease, heart failure, chronic kidney disease, diabetes, and/or severe obesity. Model inputs were informed by existing literature. The base-case analysis estimated incremental RSV cases, RSV-related healthcare resource use and deaths, discounted quality-adjusted life years (QALYs) lost, and incremental cost-effectiveness ratios (ICERs) from a societal perspective (direct and indirect costs). Sensitivity analyses assessed varying model inputs and parameter uncertainty, while scenario analyses estimated ICERs from a healthcare sector perspective (direct costs only) and among condition-specific subgroups. RESULTS: Overall, 7,957,333 of the total 24,260,162 increased-risk adults aged 18-49 years received adjuvanted RSVPreF3 vaccination, which was estimated to avoid 869,819 RSV cases over 5 years, including 303,924 RSV-related outpatient visits, 444 RSV-related deaths, and 20,540 QALY losses versus no vaccination. The corresponding ICER was $61,717 per QALY gained from the societal perspective. Scenario analyses estimated that adjuvanted RSVPreF3 vaccination was cost-saving or cost-effective among all condition-specific subgroups based on a hypothetical willingness-to-pay threshold of $150,000 per QALY gained. Results were robust across sensitivity analyses. CONCLUSIONS: Model findings suggest considerable potential public health benefits and cost-effectiveness of adjuvanted RSVPreF3 vaccination among US adults aged 18-49 years at increased risk for severe RSV disease.