FDA Approves Pfizer's RSV Vaccine ABRYSVO® for At-Risk Adults 18-59

NEW YORK, NY, USA I October 22, 2024 I Pfizer Inc. announced that the U.S. Food and Drug Administration (FDA) has approved ABRYSVO (Respiratory Syncytial Virus Vaccine), a bivalent RSV prefusion F (RSVpreF) vaccine. This vaccine is designed to prevent lower respiratory tract disease (LRTD) caused by RSV in individuals aged 18 to 59 who are at increased risk. This approval expands the vaccine's indication, which previously covered adults 60 years and older, and also includes pregnant individuals at 32 to 36 weeks of gestation to protect infants from birth up to six months old.

Aamir Malik, Chief U.S. Commercial Officer and Executive Vice President of Pfizer, highlighted the significance of this approval, stating that RSV poses a serious threat to younger adults with chronic conditions. He emphasized Pfizer's commitment to alleviating the burden of RSV among high-risk adults through this expanded vaccine indication.

The FDA's approval is grounded in efficacy data from the pivotal Phase 3 clinical trial MONeT (RSV Immunization Study for Adults at Higher Risk of Severe Illness). This trial evaluated the safety, tolerability, and immunogenicity of ABRYSVO in adults with chronic medical conditions that increase their risk for RSV-related LRTD. Pfizer plans to disseminate the MONeT trial results in a peer-reviewed scientific journal and present them at an upcoming scientific conference.

In the United States, 9.5% of adults aged 18 to 49 have underlying chronic conditions such as obesity, diabetes, chronic obstructive pulmonary disease (COPD), heart failure, chronic kidney disease, and asthma. This percentage rises to 24.3% among adults aged 50 to 64, underscoring the importance of vaccination in these populations.

RSV is a common and contagious virus that can cause severe respiratory illness, particularly in individuals with chronic health conditions. Chronic cardiovascular disease, chronic lung disease, moderate or severe immune compromise, diabetes with complications, and severe obesity are known to increase the risk of severe RSV. The virus has two major subgroups, RSV-A and RSV-B, both of which can cause disease and may co-circulate or alternate predominance seasonally.

ABRYSVO is the only RSV vaccine currently approved to protect adults aged 60 and older, adults 18 and older at increased risk of RSV-LRTD, and infants through maternal immunization. The vaccine is designed to provide broad protection against RSV-LRTD, regardless of the virus subgroup. The RSV fusion protein (F), in its prefusion state, is a key target for neutralizing antibodies and forms the basis of Pfizer's RSV vaccine. Variations in the F protein sequence among RSV-A and RSV-B are concentrated in an important antigenic site targeted by potent neutralizing antibodies.

In May 2023, the FDA approved ABRYSVO for preventing LRTD caused by RSV in individuals aged 60 and older. In June 2024, the Advisory Committee on Immunization Practices (ACIP) updated its recommendation to include RSV vaccines for adults aged 75 and older, as well as those aged 60 to 74 at increased risk for severe RSV disease. By August 2023, the FDA had also approved ABRYSVO for the prevention of LRTD and severe LRTD in infants from birth up to six months old through maternal immunization at 32 to 36 weeks of gestation. ACIP followed with a recommendation for maternal immunization to protect newborns during the RSV season, typically from September through January in most of the continental U.S.

Furthermore, in August 2023, Pfizer announced that the European Commission granted marketing authorization for ABRYSVO for both older adults and maternal immunization to protect infants. ABRYSVO has also received approvals for these indications in multiple countries worldwide.