The respiratory syncytial virus (RSV) vaccines were about 80% effective in older adults during the 2023-24 respiratory disease season, which was the first season after the shot was approved in the US, according to a report published Thursday in The Lancet.
Researchers said the RSV vaccines gave approximately 80% protection against severe disease and hospitalization, intensive care unit admission and death in 28,271 people over 60 who were hospitalized but not immunocompromised. The vaccines exhibited 77% effectiveness against less severe disease in older adults who visited an emergency department but weren’t hospitalized.
Among 8,435 hospitalisations for RSV in those who were immunocompromised, the vaccine was 73% effective against hospitalization.
People 75 and older had the highest risk of severe disease and were most likely to be hospitalized, the authors noted.
The study was funded by the Centers for Disease Control and Prevention. The CDC and nine US health care systems and research centers who were part of the CDC’s VISION Network collaborated on the study. The sites represented 230 hospitals and 245 emergency departments.
Unlike this data study, clinical trials for the RSV vaccine were underpowered to assess the effectiveness of the vaccines against severe disease that required hospitalization, the authors wrote. “Addressing this gap in evidence, we were able to use the power of big data to determine RSV vaccine effectiveness, information needed to inform vaccine policy,” Shaun Grannis, MD, a study coauthor and professor at Indiana University, said in a statement. “As a data scientist and a family practice physician, I encourage older adults to follow CDC guidance and get vaccinated for RSV as we enter this year’s and every year’s respiratory disease season.”
RSV season starts in the US during late September or early October and continues through March or early April.
“No vaccine is 100% effective. An 80% vaccine effectiveness rate is quite impressive and higher than we see, for example, with the influenza vaccine,” Brian Dixon, PhD, a co-author and interim director and a research scientist with the Clem McDonald Center for Biomedical Informatics at Regenstrief Institute, said in the statement.
