Pfizer’s Abrysvo is the first respiratory syncytial virus vaccine that can be used for adults less than 50 years of age. Tuesday’s label expansion covers younger adults who are deemed at higher risk of RSV-related lower respiratory tract disease.
Pfizer on Tuesday announced that the FDA has greenlit its respiratory syncytial virus vaccine Abrysvo to prevent lower respiratory tract disease in adults aged 18 to 59 years.
Abrysvo is the first and only respiratory syncytial virus (RSV) shot that can be used in adults younger than 50 years of age, and now “offers the broadest RSV vaccine indication for adults,” according to Pfizer.
Tuesday’s label expansion covers younger adults who are deemed at higher risk of RSV-related lower respiratory tract disease (LRTD). In the U.S., around 9.5% of adults aged 18 to 49 have an underlying chronic condition such as diabetes or obesity and are more susceptible to RSV LRTD and associated hospitalizations.
Pfizer Chief U.S. Commercial Officer Aamir Malik said in a statement that the company is “proud” to have secured the FDA’s first approval for an RSV vaccine in younger adults, for whom the virus “represents a significant threat,” especially in those with “certain chronic conditions.” Abrysvo is still the only vaccine option for pregnant women from 32 through 36 weeks of gestation, to elicit protection in infants from birth through six months.
Tuesday’s label expansion for Abrysvo was supported by the shot’s “inferred efficacy” in the Phase III MONeT trial. Pfizer revealed topline data from MONeT in April 2024, noting that the Abrysvo met its primary efficacy endpoint, eliciting a non-inferior immune response in younger adults as in participants aged 60 years and above.
The pharma did not provide specific data at the time, but said in its announcement on Tuesday that it will submit findings for publication in a peer-reviewed journal and for presentation at an upcoming conference.
Abrysvo’s expansion comes after the U.S. Centers for Disease Control and Prevention narrowed its RSV vaccination guidelines. In June 2024, the CDC’s Advisory Committee on Immunization Practices (ACIP) said that RSV shots would only be recommended for all seniors aged 75 and above. Meanwhile, for the 60-to-74-year age group, panel advised that vaccines should only be given to those who are at risk of severe disease.
At the time, the ACIP deferred its vote on the use of RSV vaccines in younger seniors aged 50 to 59 years.
Despite the smaller patient pool, Tuesday’s expansion could help Pfizer secure a better market position for Abrysvo—and potentially narrow the gap with RSV frontrunner GSK. The British pharma beat Pfizer in the RSV race, winning the FDA’s approval for its own vaccine Arexvy a month earlier. Arexvy is indicated for adults aged 60 years and above, and for those 50 to 59 years old who are at risk of RSV LRTD.
GSK’s first-to-market advantage has proven difficult for its competitors to overcome. In December 2023, CEO Emma Walmsley told investors that Arexvy had captured the majority of retail vaccinations in the U.S. and that it was on its way to becoming a blockbuster asset for the pharma.
