Study Finds RSV Vaccines Protect Older Adults with 75 Percent Effectiveness

A comprehensive new study published in JAMA Network Open revealed that respiratory syncytial virus (RSV) vaccines provide strong protection for adults aged 60 and older, with approximately 75 percent effectiveness against RSV-associated respiratory illness. 

In the study, researchers analyzed data from more than 787,000 older adults tested for RSV between October 2023 and April 2024, finding the vaccine equally effective for both 60- to 74-year-olds and those 75 and older. The protection extended to decreasing emergency department visits and hospitalizations for RSV at similar rates. For older adults with compromised immune systems, the RSV vaccine still offered substantial protection, though slightly reduced at 67 to 73 percent. However, the study identified significantly lower effectiveness (29 to 44 percent) among stem cell transplant recipients specifically.

The researchers also examined safety data from more than 4.7 million vaccine recipients, addressing concerns about rare adverse events. Their analysis found no elevated risk of immune thrombocytopenic purpura following vaccination. They did detect a small but statistically significant increased risk of Guillain-Barré syndrome (GBS), with approximately 11 excess cases per million vaccine doses.

The two available vaccines included in the study showed different safety profiles. The RSVPreF vaccine (Abrysvo) was associated with 18.2 excess GBS cases per million doses, while the RSVPreF3+AS01 vaccine (Arexvy) showed a lower rate of 5.2 excess cases per million.

The study utilized Epic Cosmos, an electronic health record platform with more than 270 million patient records, allowing researchers to analyze real-world vaccine performance on an unprecedented scale.

“These observations should inform clinicians’ choices and patient instructions,” noted study authors, led by Sarah E. Fry and colleagues from Case Western Reserve University.