The US Food and Drug Administration (FDA) has expanded the approved age indication for GSK's respiratory syncytial virus vaccine, Arexvy, for adults aged 18 to 49 who face a higher risk of lower respiratory tract disease caused by RSV. The vaccine was previously approved to prevent RSV-related lower respiratory tracts in adults aged 60 and older, and those aged 50 to 59 who are at increased risk of complications. The broader age indication addresses an unmet medical need among younger adults with underlying health conditions. The decision was backed by results from a Phase 3b study that showed the vaccine produced an immune response in adults 18 to49 that was non-inferior to those aged 60.