Efficacy of a Novel Nanoparticle RSV Vaccine in Preventing Infection in Older Adults: Phase III Clinical Trial

In this susceptible population, respiratory syncytial virus (RSV) can cause severe lower respiratory tract illness (LRTI), which can result in substantial morbidity and mortality. Adults who have RSV infection face a substantial burden. In this study, a Phase III, randomized, double-blind, placebo-controlled trial evaluated the effectiveness of a liposome-encapsulated perfusion F protein nanoparticle-based RSV vaccine (Nano-RSV) in preventing RSV infection. Adults who were enrolled and 60 years of age or older were given either Nano-RSV or a placebo. The incidence of laboratory-confirmed RSV LRTI exhibiting three or more symptoms (cough, fever, and shortness of breath) was the main outcome. Severity of symptoms and hospitalization rates for RSV LRTI were secondary endpoints. When compared to a placebo, the Nano-RSV vaccine dramatically lowered the risk of RSV LRTI (vaccine efficacy: 82.6%, 95% CI: 74.1–90.2%). RSV LRTI-related hospitalization rates were likewise markedly lower in the immunization group. The safety profile of the Nano-RSV vaccine was comparable to that of a placebo, and it was well-tolerated. These results imply that Nano-RSV may prove to be a secure and reliable prophylactic against RSV infection and its sequelae in the elderly.