Respiratory Syncytial Virus Prefusion F Vaccination: Antibody Persistence and Revaccination

Background Respiratory syncytial virus (RSV) causes substantial respiratory disease. Bivalent RSV prefusion F (RSVpreF) vaccine is licensed in ≥60-year-olds. RSVpreF was well-tolerated and immunogenic in a phase 1/2 study. We evaluated antibody persistence after initial vaccination and safety and immunogenicity after revaccination from this study. Methods Healthy adults were randomized to receive both initial vaccination and revaccination 12 months later with either placebo or RSVpreF 240 µg (±Al(OH)3). RSV-A and RSV-B geometric mean neutralizing titers (GMTs) were measured through 12 months after both vaccinations. Tolerability/safety was assessed. Results There were 263 participants revaccinated (18−49-years-old, n=134; 65−85-years-old, n=129). Among 18−49-year-olds and 65−85-year-olds, respectively, geometric mean fold rises (GMFRs) for both RSV subgroups (RSV-A; RSV-B) 1 month after initial RSVpreF vaccination were 13.3−20.4 and 8.9−15.5 compared with levels before initial vaccination; corresponding GMFRs 12 months after initial vaccination were 4.1−5.0 and 2.6−4.1. GMFRs 1 month after revaccination compared with levels before revaccination were 1.4−2.3 and 1.4−2.2 for 18−49-year-olds and 65−85-year-olds, respectively. Peak GMTs after revaccination were lower than those after initial vaccination. GMTs 12 months after initial vaccination and revaccination were similar, with GMFRs ranging from 0.7−1.6. No safety signals occurred. Conclusions RSVpreF revaccination was immunogenic and well-tolerated among adults. NCT03529773