The respiratory syncytial virus (RSV) can be particularly dangerous for older people with chronic medical conditions.
Each year in the United States, RSV infections in older adults result in up to 160,000 hospitalizations and as many as 10,000 deaths, according to the Centers for Disease Control and Prevention (CDC), which in June 2023 recommended RSV vaccination for adults age 60 and older.
As an initial evaluation of this recommendation, a large multicenter study led by the CDC and Vanderbilt University Medical Center found that adults 60 and older who received an RSV vaccine were significantly less likely to be hospitalized with RSV than those who were not vaccinated.
The researchers studied adults 60 and older who were hospitalized with acute respiratory illness and compared RSV vaccination in patients with RSV and those with no RSV infection. The study was conducted in 19 states between October 2023 and March 2024.
The results, published Sept. 4 in the Journal of the American Medical Association (JAMA), demonstrated that RSV vaccination was 75% effective in preventing RSV-associated hospitalizations. The study was led by the Investigating Respiratory Viruses in the Acutely Ill (IVY) Network, which is coordinated from VUMC.
“This is an important study that shows RSV vaccination was highly effective last winter in preventing older Americans from becoming severely ill and being hospitalized with RSV,” said Wesley Self, MD, MPH, principal investigator of the IVY Network, Senior Vice President for Clinical Research and professor of Emergency Medicine at VUMC.
“This provides real-world evidence that RSV vaccination prevented about three-quarters of RSV hospitalizations that would have occurred among vaccine recipients if they had not been vaccinated,” Self said.
“These findings provide one of the first demonstrations of the effectiveness of RSV vaccines in protecting older adults,” added Carlos Grijalva, MD, MPH, professor of Health Policy and Biomedical Informatics at VUMC, and an IVY investigator. “It will be important to continuously evaluate the effectiveness of RSV vaccines in future seasons.”
Diya Surie, MD, of the CDC’s Coronavirus and Other Respiratory Viruses Division, was corresponding author of the report, which was co-authored by Self and Grijalva. Other VUMC co-authors were Yuwei Zhu, MD, MS, senior associate in Biostatistics who served as the study’s lead biostatistician, and biostatistician Cassandra Johnson, MS.
“Our findings underscore the potential of RSV vaccination in mitigating hospitalization risks among older adults,” Zhu said. “As we move forward, it is vital that we continue to monitor and evaluate the effectiveness of the vaccine in future seasons to ensure continued protection for this vulnerable population.”
The results of the study were presented to CDC’s Advisory Committee on Immunization Practices (ACIP) this spring.
In June, the CDC strengthened its recommendation for RSV vaccination, and it now recommends that all adults 75 and older and those 60 to 74 who are at increased risk for severe RSV disease receive RSV vaccination.
The study was supported by a CDC contract to VUMC.
