Study shows surprising two-year shield
Vanderbilt University Medical Center
One shot of an RSV vaccine protects adults ages 60 or older
from RSV-associated hospitalization and critical illness during two consecutive
RSV seasons, according to a study published in JAMA on August
30 by the IVY Network research group.
RSV causes substantial seasonal illness during fall and
winter in the U.S., with an estimated 100,000-150,000 hospitalizations and
4,000-8,000 deaths occurring annually among adults 60 or older.
The results reinforce the recommendations for RSV vaccines
in older adults and lay the groundwork for understanding how long a single dose
of the vaccine may be effective, according to Wesley Self, MD, MPH, principal
investigator for the IVY Network and Senior Vice President for Clinical
Research at Vanderbilt University Medical Center.
"These results clearly demonstrate that the RSV
vaccines prevent hospitalizations and critical illness due to RSV infection
among older Americans," Self said. "It is exciting to see the public
health benefits of this new vaccination program."
Investigators used data from a multicenter hospital network known as the IVY Network (The Investigating Respiratory Viruses in the Acutely Ill Network) to assess RSV vaccine effectiveness. They used a test-negative, case-control study design among 6,958 persons 60 years or older who had been hospitalized with acute respiratory illness at one of 26 hospitals in 20 US states during two RSV seasons from October 1, 2023-March 31, 2024 and October 1, 2024-April 30, 2025.
Overall, vaccination reduced the risk of RSV hospitalization
by 58% during two RSV seasons, including 69% in the first year after
vaccination and 48% in the second year after vaccination.
"Our data show that the beneficial effects of RSV
vaccines appear to wane over time," Self said. "Redosing the vaccine
at some interval after the initial dose could be a strategy to maintain
protection over longer periods of time. It will be important to continue to
closely monitor vaccine effectiveness over time to understand how long the
benefit lasts after a single dose and if repeat dosing should be
considered."
Current RSV vaccine recommendations are for all adults aged
75 years and older and those aged 60-74 years who are at an increased risk of
severe RSV.
This study was funded by the U.S. Centers for Disease Control and Prevention (CDC) via award 75D30122C14944. EDITOR'S NOTE: This research was funded pre-Trump, pre-Musk and pre-RFK Jr. I searched for news about grants for RSV research and saw several in 2023-4, but none since Trump took office. - W. Collette
