FDA Approves Abrysvo for Adults 18-59 at Increased Risk for RSV
Abrysvo is the only RSV vaccine approved for use in this age group.
Pfizer’s respiratory syncytial virus (RSV) vaccine Abrysvo has been approved by the FDA for the prevention RSV-associated of lower respiratory tract disease in individuals aged 18 to 59 who are at increased risk of disease.1 This unadjuvanted, bivalent RSV prefusion F (RSVpreF) vaccine is the first and only RSV vaccine indicated for adults younger than 50 years.
Abrysvo is the only RSV vaccine approved for use in adults aged 18-59. | Image credit: kitsawet - stock.adobe.com
Approval for this new indication was based on data from the pivotal phase 3 MONET clinical trial (NCT05842967), where investigators evaluated the safety, tolerability, and immunogenicity of Abrysvo in a cohort of adults at risk for RSV-associated diseases due to certain chronic medical conditions.
This approval is crucial for at-risk individuals in this age group: according to research published in Infectious Disease Therapy,2 9.5% of US adults have an underlying chronic condition—such as asthma, diabetes, chronic obstructive pulmonary disease, heart failure, and/or chronic kidney disease—that increases their risk of developing RSV-associated lower respiratory tract disease that may require hospitalization.
“RSV represents a significant threat to younger adults with certain chronic conditions. After decades of vaccine research…we now have the opportunity to help alleviate the burden of RSV in this high-risk adult population,” said Aamir Malik, Chief US commercial officer and executive vice president at Pfizer.1
Pfizer is one of 3 FDA approved RSV vaccines: GSK’s Arexvy was approved on May 3, 2023, and Moderna’s mRNA vaccine mRESVIA was approved in early 2024. Abrysvo received initial FDA approval on May 31, 2023,3 and remains the only RSV vaccine that is also approved4 for use in pregnant women 32 to 36 weeks gestational age to protect infants from birth through 6 months of age (MATISSE clinical trial, NCT04424316). Additional research has shown that Abrysvo remains efficacious in older adults through a second RSV season (RENOIR clinical trial, NCT05035212).
READ MORE: The Respiratory Disease Trifecta: What to Know About COVID-19, Flu, and RSV
At their June 2024 meeting, the CDC’s Advisory Committee on Immunization Practices (ACIP) voted to update their recommendation for RSV vaccination in older adults: All adults aged 75 years or older, as well as adults aged 60 to 74 years, who are at an increased risk for severe RSV should receive a single dose of an RSV vaccine. At the September 2023 ACIP meeting, Abrysvo was recommended for maternal immunization.
Data show that the MONET study met its co-primary immunogenicity endpoints, as well as its primary safety endpoint.5 Both RSV-A and RSV-B subgroup neutralizing responses were noninferior to those seen in RENOIR. MONET study participants also achieved “at least a 4-fold increase in serum neutralizing titers for RSV-A and RSV-B” in the 1 month period after Abrysvo administration compared with pre-vaccination. The vaccine was well-tolerated among study participants, and safety findings were consistent with previous studies of Abrysvo across other populations.5
Of note regarding the study population, Pfizer announced that the company had met its diversity recruitment goals for the MONET clinical trial, with a study population that “mirror[ed] the diverse US population and had a balanced representation across underlying medical conditions.”5
An additional clinical trial evaluating Abrysvo in children aged 2 to 18 years at higher risk for RSV is also underway.5
READ MORE: Immunization Resource Center
