Clinical and economic impact of bivalent respiratory syncytial virus prefusion F (RSVpreF) vaccination in older adults: a cost-effectiveness analysis for Chile

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract disease in older adults in Chile. Chile's National Immunization Technical Advisory Group (NITAG) recommended RSV vaccination for adults aged ≥60 years with risk factors for severe illness. This study estimated the cost-effectiveness of bivalent RSVpreF vaccination among at-risk older adults in Chile. RESEARCH DESIGN AND METHODS: A population-based Markov model projected RSV-related outcomes under no vaccination and RSVpreF vaccination over the cohort lifetime. Cost-effectiveness was assessed from healthcare and societal perspectives in 2025 Chilean Pesos (CLP) and US Dollars (US$), with costs and outcomes discounted at 3% annually. Sensitivity analyses tested the model robustness. RESULTS: RSVpreF vaccination was projected to prevent 14,956 hospitalizations, 50,419 emergency department visits, and 124,849 physician office visits; avert CLP76 billion (US$82 million) in direct medical costs and CLP305 billion (US$328 million) in indirect costs; and generate 7,079 quality-adjusted life-years (QALYs). At a threshold of CLP15,977,348 (US$17,180) per QALY gained, the maximum cost-effective vaccine price was CLP100,480 (US$108) and CLP265,261 (US$285) from the healthcare and societal perspectives respectively. CONCLUSIONS: RSVpreF vaccination would reduce RSV burden and likely be cost-effective for older adults in Chile.