Efficacy, Immunogenicity, and Safety of the Bivalent Respiratory Syncytial Virus (RSV) Prefusion F Vaccine in Older Adults Over 2 RSV Seasons

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract illness (LRTI) in older adults. RSV prefusion F (RSVpreF) is a bivalent stabilized prefusion F vaccine containing RSV-A and RSV-B antigens. In this phase 3 trial in persons aged ≥60 years, RSVpreF demonstrated vaccine efficacy (VE) of 88.9% and 77.8% against RSV-associated LRTI with ≥3 symptoms at the end of RSV seasons 1 and 2, respectively. We describe final safety and efficacy results and present immunogenicity data.

This study was conducted over 2 RSV seasons. Participants were randomized (1:1) to RSVpreF 120-µg or placebo. A secondary objective was to describe RSVpreF immunogenicity 1 month post-vaccination and before season 2 visits in participants from the United States and Japan.