RSV vaccine effective in the real world, manufacturer study finds
The respiratory syncytial virus (RSV) vaccine was 92% effective against hospitalization or ED visits due to RSV in an analysis of adults ages 60 years or older vaccinated during the 2023-2024 season.
A respiratory syncytial virus (RSV) vaccine showed effectiveness against acute respiratory illness, including severe disease, an industry-funded study found.
The retrospective test-negative case-control study included adults ages 60 years and older in a single health care system. All patients had ED visits or hospitalizations for acute respiratory infections in November 2023 to April 2024, the vaccine's first postlicensure season. Controls in the primary analysis tested negative for RSV, human metapneumovirus, influenza, and COVID-19 and positive for a non-vaccine-preventable pathogen. The exposure was receipt of an RSV vaccine 21 or more days before the infection. Pfizer funded the study and participated in the interpretation of data. Results were published Oct. 21 by Clinical Infectious Diseases.
Overall, 8,965 ED visits or hospitalizations with RSV testing were included. A total of 7.8% of patients were positive for RSV, and of these, 0.3% had received the vaccine versus 3.6% of controls. The adjusted vaccine efficacy was 92% (95% CI, 64% to 98%) against either of the study's outcomes. Efficacy was estimated to be similar among patients with conditions that put them at higher risk (92% [95% CI, 65% to 98%]); those in the oldest subgroup, who were ages 75 years and older (95% CI; 95% CI, 60% to 99%); those with critical outcomes, defined as ICU admission, mechanical ventilation, respiratory failure, vasopressor use, or death [90%; 95% CI, 16% to 99%); and those with severe disease, defined as an ED visit or hospitalization requiring oxygen (92%; 95% CI, 35% to 99%).
Limitations of the study included a shorter follow-up time after vaccination than in other real-world studies, which likely contributed to higher vaccine efficacy estimates, and low vaccine uptake in the first season after licensure, which came before the vaccine was routinely recommended for adults ages 75 years and older and those ages 60 to 74 years at increased risk.
“With pending expansion of recommendations to adults aged 50-59 years, continued evaluation of the potential protective benefits of this vaccine is warranted,” the authors wrote.