RSV Vaccine Highly Effective in Preventing Severe Illness in Older Adults

The Respiratory Syncytial Virus Prefusion F (RSVpreF) vaccine is highly effective against RSV-related lower respiratory tract disease (LRTD), keeping adults 60 years and older, especially those at high risk, out of the hospital or emergency room, according to a recent study published in JAMA Network.

RSV is a major cause of severe lung infections, especially in older adults and those with other health commorbidities. Each year in the U.S., RSV leads to about 160,000 hospital stays and 120,000 emergency department visits for people 65 years and older, according to the study.

To help prevent these infections, the U.S. approved the RSVpreF vaccine for adults 60 years and older in 2023, recommending it only based on individual’s decisions with their doctors.

While early trials showed the vaccine could prevent RSV infections, there wasn’t enough data about effective it was for serious cases or in high-risk groups.

Researchers of Kaiser Permanente, Pfizer and the University of California examined its effectiveness in adults 60 years and older from Kaiser Permanente in Southern California who visited the hospital or ER for LRTD between November 24, 2023, and April 9, 2024.

Patients with RSV infections were compared to two groups of controls: one with no RSV and specific other illnesses, and another with no RSV but any other lung issues.

To ensure accuracy, unused swabs from routine testing were tested for RSV. Data were analyzed from May to September 2024.

Researchers mainly focused on whether the vaccine, given at least 21 days before illness, protected against the first severe RSV-related hospital or ER visit.

Out of 7,047 hospital or emergency visits for RSV-related lung infections, patients were at an average age of 77, with 54% being women.

Patients were diverse, with 33% being Hispanic, 37% non-Hispanic White, 17% non-Hispanic Black and 12% Asian or Pacific Islander.

Most (93%) had other health conditions, and 14% were immunocompromised.

The RSVpreF vaccine showed 91% effectiveness using strict controls and 90% effectiveness with broader controls, providing strong protection against severe RSV cases.

Outside of effective results, the study strengths include its large sample size and focus on high-risk adults, enhancing its importance to the RSV vaccine population.

However, less than 5% of study participants with LRTD were vaccinated, which makes it harder to apply the study's findings to the broader population.

Additionally, the short time the participants were monitored and the lack of complete RSV testing in younger and healthier folks might have influenced the accuracy and reliability of the study's results.

Authors do suggest that for every 250 people vaccinated, one emergency room visit, or hospital stay due to RSV could be prevented during the first season. It’s recommended that the use of the RSVpreF vaccine in older adults could reduce serious RSV cases and ease the overall burden on healthcare.