FDA Considers Broader Use of GSK’s RSV Vaccine for At-Risk Adults
While the final regulatory decision is expected in the first half of 2026, the expanded use of Arexvy, to include younger at-risk adults, could help protect more than 21 million Americans vulnerable to RSV.
The FDA has accepted GSK’s application to expand the approved use of its respiratory syncytial virus (RSV) adjuvanted vaccine, Arexvy. Currently indicated for adults aged 60 years and over — and extended to those aged 50–59 years at increased risk — GSK is seeking approval for further use in adults aged 18 to 49 years with underlying medical conditions that elevate their risk of severe RSV-related illness (1).
This latest regulatory submission to FDA leverages new data from a Phase IIIb study evaluating the vaccine’s immune response and safety profile in adults aged 18 to 49 years with underlying health conditions (1). The results demonstrate that this younger adult subset mounted strong immune responses with safety and tolerability outcomes consistent with those previously documented in older adults and other high-risk groups.
RSV is a common but potentially serious respiratory infection. Often presenting cold-like symptoms, RSV can lead to severe complications such as pneumonia and the worsening of underlying cardiopulmonary conditions. Although infants and older adults have historically been considered the most vulnerable, evidence highlights the danger posed to younger adults with comorbidities such as chronic lung conditions, diabetes, congestive heart failure, and weakened immune systems (2).
If approved, the expanded use of the RSV adjuvanted vaccine could have a considerable impact for the estimated 21 million U.S. adults aged 18 to 49 years at heightened risk of severe RSV complications (1). It is also expected to reduce severe RSV cases, hospitalizations, and intensive care admissions through broader prevention strategies. This not only improves individual health outcomes but also helps ease seasonal pressure on healthcare systems (2) — both key public health priorities that have been highlighted by the CDC and other organizations (3,4).
However, GSK faces rising competition in the RSV vaccine market, as both Moderna and Pfizer are seeking regulatory approval for similar expanded indications with their own vaccines — mRESVIA and Abrysvo respectively — for at-risk adults under 60 years of age (5). The FDA’s review also comes at a time of global regulatory activity, with European and Japanese authorities also evaluating Arexvy’s expanded use in younger adults.
A decision on Arexvy’s expanded indication is expected in the first half of 2026. If approved, it would mark a major step forward in protecting at-risk American adults under 50 years of age, that have so far been an often-overlooked population in RSV prevention strategies. For GSK, securing this approval would not only strengthen its competitive position but also reinforce the public health value of adult RSV vaccination across age groups.
References
1. GSK. US FDA Accepts Application to Review Expanded Use of GSK’s RSV Vaccine, Arexvy, for Adults 18-49 at Increased Risk. Press Release, July 14, 2025.
medRxiv. Chronic Conditions and Risk of Severe Outcomes Among Adults Aged 18-59 Years with Medically-Attended RSV Illness in the United States. Preprint. June 18, 2025.
Penders, Y.; Brusselle, G.; Falsey, A.R.; et al. Burden of Respiratory Syncytial Virus Disease in Adults with Asthma and Chronic Obstructive Pulmonary Disease: A Systematic Literature Review. Curr. Allergy Asthma Rep., 2025, 25 (1), 14.
Molinari, N.M.; Ortega-Sanchez, I.R.; Messonnier, M.L.; et al. The Annual Impact of Seasonal Influenza in the US: Measuring Disease Burden and Costs. Vaccine, 2007, 25 (27), 5086–5096.
CDC. RSV Vaccine Guidance for Adults. Guidance. July 8, 2025.