Novel RSV Vaccine to Prevent Serious Respiratory Illness

Jun 23, 2024

Photo Credit: Chan2545

Serious respiratory illnesses could be prevented by a bivalent RSV prefusion F vaccine.

A bivalent RSV prefusion F vaccine elicited a robust immune response, resulting in durable vaccine efficacy through two RSV seasons. The immune responses that were documented in the phase 3 RENOIR trial were consistent across RSV-A/RSV-B subgroups, and across age, race, and comorbidity subgroups.

“RSV is a common cause of serious respiratory illness, especially in individuals with comorbidities,” said Dr Daniel Eiras MD, MPH, from Pfizer, NY, in the US. A bivalent stabilised RSV prefusion F vaccine was tested in the phase 3 RENOIR study (NCT05035212), in 38,861 participants of 60 years of age. All participants were healthy or had stable chronic conditions. They were randomised 1:1 to receive the RSV vaccine or a placebo. Dr Eiras and co-investigators followed patients for 2 years and documented all ‘acute respiratory illness’ events.

After 2 years, 10 events of RSV-lower respiratory tract illness were reported in the vaccinated arm compared with 54 events in the placebo arm. This reflects a vaccine efficacy of 81% across the 2 years (95% CI 63.3–91.6). In the first year, the vaccine’s efficacy was 88.9% and in the second year, the efficacy had dropped to 77.8%. The vaccine’s efficacy was consistent across subgroups, such as age groups, patients with high-risk conditions, and those with either RSV-A or RSV-B infections. “We observed robust immune responses for both RSV-A and RSV-B subgroups, as well as for patients with various cardiopulmonary conditions,” added Dr Eiras.

The findings of the RENOIR study show that the tested RSV vaccine has the potential to prevent serious respiratory illness in individuals who are at increased risk for serious illness after an RSV infection.

Medical writing support was provided by Robert van den Heuvel.