In June 2023, the US Centers for Disease Control and Prevention (CDC) recommended respiratory syncytial virus (RSV) vaccination for adults aged 60 years and older1 based on high efficacy against RSV lower respiratory tract disease demonstrated in prelicensure randomized trials.2,3 Prelicensure trials were not powered to assess efficacy against RSV-associated hospitalization, excluded immunocompromised patients, and underrepresented other groups at increased risk of severe RSV disease, including adults aged 75 years and older. This study evaluated RSV vaccine effectiveness (VE) against RSV-associated hospitalization among adults aged 60 years and older during the first season of use.