RSV Vaccine Proves 78 to 80 Percent Effective Against Infection, ED/UC Visits, and Hospitalization

New findings published in The Lancet Infectious Diseases show that the “estimated effectiveness of the respiratory syncytial virus (RSV) among older US veterans in the 2023-2024 respiratory virus season against infection, emergency department/urgent care (ED/UC) visits, and hospitalization was 78%, 79%, and 80%, respectively.” CIDRAP has the news.

The researchers used “electronic health records at the Veterans Health Administration (VHA) to emulate a target trial comparing a single dose of RSV vaccine…with no vaccination in veterans aged 60 years and older.” The vaccine recipients were matched with “as many as four unvaccinated controls.”

Along with the findings laid out in the first paragraph, “estimated VE against RSV infection was 72.3% (57.9% to 84.6%) in veterans aged 80 years and older and 71.6% (55.4% to 85.2%) in those with weakened immune systems.” During a median follow-up of 124 days, “the incidence of RSV infection was 1.7 events per 1,000 person-years (88 total infections) among vaccinated participants and 7.3 per 1,000 person-years (372 infections) among the unvaccinated.”

A related commentary in the journal cautioned that “veterans are not representative of the United States as a whole.” The writers also brought up the fact that “the median follow-up was only 4.1 months, compared with data from over two seasons available from the vaccine trials.” They assert that “more research is needed to determine the optimal RSV vaccination schedule, VE in women in a real-world setting, and VE against post-RSV ICU admissions, complications, and death;” additionally, they advise that future studies use “diverse databases over a range of geographies.”