JAMA Network Open has published a new study demonstrating respiratory syncytial virus (RSV) vaccine effectiveness in adults 60 and older of 90% for both RSV–related hospitalization and emergency department (ED) visits.
The study provides real-world VE data based on the 2023-24 RSV season and outcomes seen among adults aged 60 years or older with hospitalizations or ED visits at Kaiser Permanente of Southern California from November 24, 2023, to April 9, 2024.
All participants had respiratory swabs collected and tested for RSV. Though previous trials have shown high VE, most trialed adults were 75 years or older. RSVpreF (Abrysvo) vaccine receipt during the first RSV season after licensure, and 21 or more days before the illness event was the main assessment.
Abrysvo was approved for use in the United States in June 2023 as a single-dose vaccine meant to protect older adults from severe RSV infections.
In total 7,047 lower respiratory tract disease hospitalizations or ED encounters with RSV testing results were included in the study. Patients had an average age of 76.8 years, 54.2% were women, 33.0% were Hispanic, and 36.9% were non-Hispanic White.
90% VE during first season
Fourteen percent of patients were immunocompromised. Overall, 8.8% (623 of 7,047) tested positive for RSV, and 3.2% (223 of 7,047) received RSVpreF. Among 6,424 test-negative controls, 221 (3.4%) were vaccinated.
When RSVpreF was received an average of 58 days before illness, the adjusted VE when the authors used broad controls was 90% (95% confidence interval [CI], 59% to 97%). It was 91% (95% CI, 59% to 98%) when they used strict controls. The efficacy held through 5 months of follow-up.
For approximately every 250 persons vaccinated, 1 RSV-related ED or hospitalization encounter could be prevented in the first season after vaccination.
"Based on our study results and RSV incidence in older adults, for approximately every 250 persons vaccinated, 1 RSV-related ED or hospitalization encounter could be prevented in the first season after vaccination," the authors wrote. "These data suggest use of RSVpreF in older adults, providing an opportunity to reduce severe medically attended RSV disease burden."
RSV causes a significant burden of disease for US adults. Each year approximately 160,000 RSV-related acute respiratory infection hospitalizations and 120,000 ED visits are related to the virus.
