![FDA APPROVED RSV prefusion F protein-based vaccine (Arexvy) over a microscope image of respiratory syncytial viruses.](http:http://assets.medpagetoday.net/media/images/110xxx/110567.jpg?width=0.8)
The FDA expanded the approval of GSK's respiratory syncytial virus (RSV) vaccine (Arexvy) to include adults ages 50 to 59 at risk of RSV-related lower respiratory tract disease (LRTD) due to underlying conditions, on Friday.
Previously the adjuvanted RSV prefusion F protein-based vaccine had been approved only for adults 60 and older; it is currently recommended for use via shared decision-making by the CDC and Advisory Committee on Immunization Practices.
According to the vaccine maker, an estimated 13 million U.S. adults ages 50 to 59 years have medical conditions -- e.g., asthma, chronic obstructive pulmonary disease, diabetes, heart failure -- putting them at increased risk of RSV-related LRTD and its serious consequences, including pneumonia and death.
"When it comes to the risks associated with RSV, age is just a number, an important number, but not the only factor to consider," Ann Falsey, MD, of University of Rochester School of Medicine in New York, said in a statement from GSK. "Many adults in this age group have underlying health conditions that place them at increased risk for serious illness with RSV infection compared with those without these conditions. Now there is a vaccine approved that can help protect them."
About 42,000 hospitalizations occur each year in the U.S. among adults ages 50 to 64 years old, according to a and meta-analysis. That compares to approximately 159,000 annual hospitalizations in U.S. adults 65 and older.
The new approval was based on results of a double-blind that demonstrated noninferior immune responses with the vaccine for 1,140 participants ages 50 to 59 (half of whom had high-risk conditions for RSV-LRTD) versus older adults. In both of the younger groups, RSV-A and RSV-B neutralization titers were similar 1 month after administration of a single vaccine dose compared to the older group.
Safety and reactogenicity were consistent with the pivotal trial data for adults 60 and over, said GSK, with most adverse events (AEs) being mild to moderate and also transient. In the adults ages 50 to 59, the most commonly reported AEs were pain at the injection site (76%), fatigue (40%), myalgia (36%), headache (32%), arthralgia (23%), erythema (13%), and swelling (10%).
Safety information in the also includes warnings about the potential for severe allergic reaction and syncope after administration, and that immunocompromised people may have a diminished immune response.