Pfizer's Abrysvo, a bivalent respiratory syncytial virus (RSV) prefusion F (RSVpreF) vaccine, has received expanded approval from the U.S. Food and Drug Administration (FDA) for the prevention of lower respiratory tract disease (LRTD) caused by RSV in individuals aged 18 through 59 years who are at increased risk for LRTD. This decision marks a significant step in broadening the protection against RSV-related illness across a wider adult population.
The FDA's approval is grounded in inferred efficacy data derived from the Phase 3 MONeT (RSV I M munizati ON Study for Adul T s at Higher Risk of Severe Illness) trial (NCT05842967). This trial assessed the safety, tolerability, and immunogenicity of Abrysvo in adults with heightened risk of RSV-associated disease due to underlying chronic medical conditions. These conditions include obesity, diabetes, chronic obstructive pulmonary disease (COPD), heart failure, chronic kidney disease, and asthma. The study's findings supported the vaccine's potential to offer protection in this vulnerable population.
Previous Approvals and Recommendations
In May 2023, Abrysvo was initially approved for the prevention of LRTD caused by RSV in individuals 60 years of age or older. Subsequently, in August 2023, the FDA approved the vaccine for maternal immunization during 32 through 36 weeks of gestational age to prevent LRTD and severe LRTD in infants from birth up to 6 months of age. The Advisory Committee on Immunization Practices (ACIP) then recommended maternal immunization to help protect newborns from seasonal RSV.
CDC Recommendations
As of October 24, the Centers for Disease Control and Prevention (CDC) recommends RSV immunization primarily for adults aged 75 and older, as well as for those aged 60 to 74 who are at increased risk of severe disease. The CDC's vaccine committee has determined that the benefits of RSV vaccination outweigh the risks in these specific patient populations.
