Respiratory Syncytial Virus Vaccine (GSK)

In the US, an estimated 21 million adults under 50 have at least one risk factor for severe RSV infection 1 * GSK plc (LSE/NYSE: GSK) today announced that the US Food and Drug Administration (FDA) has expanded the approved age indication of AREXVY (Respiratory Syncytial Virus Vaccine, Adjuvanted) to adults aged 18 to 49 years at increased risk for lower respiratory tract disease (LRTD) caused by RSV. AREXVY was previously approved in the US for the prevention of RSV-related LRTD in adults aged 60 and older, and adults aged 50–59 at increased risk for LRTD caused by RSV. This vaccine is not for use in pregnant individuals. Sanjay Gurunathan, GSK Head of Vaccines and Infectious Diseases Research and Development, said: “This age expansion can help address a significant medical need for adults in the United States at higher risk of severe RSV disease due to certain underlying conditions, and help ease pressure on the healthcare system. We are proud of this latest step in our strategy to bring RSV prevention to broader adult populations.” The annual RSV burden among US adults aged 18–49 years is about 17,000 hospitalizations, 277,000 emergency department admissions, and 1.97 million outpatient visits.2† Most hospitalizations in younger adults occur in those with chronic medical conditions which place them at increased risk for severe RSV disease (e.g. chronic cardiopulmonary, kidney or renal disease, obesity and diabetes).2† The FDA’s decision was supported by data from a Phase IIIb trial (NCT06389487) demonstrating a non-inferior immune response compared to adults aged 60 years and above.3 Vaccine efficacy was demonstrated in the earlier Phase III trial (NCT04886596).4 The safety profile was consistent with findings from the broader Phase III program that supported the initial US approval, with the most common adverse events being injection site pain, fatigue, myalgia, headache, and arthralgia within four days of vaccination.3 GSK continues to advance regulatory submissions for its RSV vaccine across multiple geographies to expand availability and support long-term growth objectives. AREXVY contains recombinant RSV glycoprotein F stabilized in the prefusion conformation (RSVPreF3). This antigen is combined with GSK’s proprietary AS01E adjuvant before administration. The use of this vaccine should be in accordance with official recommendations. As with any vaccine, a protective immune response may not be elicited in all vaccinees. The vaccine has been approved for the prevention of RSV-LRTD in individuals 60 years of age and older in 70 countries. In addition, it is approved for use in individuals aged 50–59 who are at increased risk due to certain underlying medical conditions in more than 60 countries. In the European Economic Area it is approved for adults aged 18 years and older. The GSK proprietary AS01 adjuvant system contains STIMULON QS-21 adjuvant licensed from Antigenics LLC, a wholly owned subsidiary of Agenus Inc. STIMULON is a trademark of SaponiQx Inc., a subsidiary of Agenus. NCT06389487 is a Phase IIIb, open-label multi-country immunogenicity trial to evaluate the non-inferiority of the immune response and evaluate safety in participants aged 18–49 at increased risk for lower respiratory tract disease (LRTD) caused by RSV (n=426), compared to participants aged 60 years and above (n=429) after a single dose of GSK’s RSV vaccine. An additional cohort of 603 participants aged 18–49 was followed up for adverse events separate to safety follow up of the initial cohort. A total of 1,458 participants were enrolled across 52 locations in six countries, including 16 US sites. The study assessed the immune response in participants aged 18–49 with pre-defined stable chronic diseases leading to an increased risk for RSV disease, compared to those aged 60 years and above. The trial’s primary endpoints were RSV-A and RSV-B neutralization titres of adults aged 18–49 years at one month after the vaccine administration compared to adults aged 60 and older. There were also safety and immunogenicity secondary and tertiary endpoints. Safety and reactogenicity data were consistent with results from the initial data read out in NCT04886596. The most common local adverse event was pain. The most common systemic adverse events were myalgia, fatigue and headache, which were largely transient and mild to moderate in intensity. About RSV in adults RSV is a common contagious virus affecting the lungs and breathing passages and impacts an estimated 64 million people of all ages globally every year.5 Adults can be at increased risk for RSV disease due to certain comorbidities, immune compromised status, or advanced age.6 RSV can exacerbate certain conditions, including chronic obstructive pulmonary disease (COPD), asthma, and chronic heart failure and can lead to severe outcomes, such as pneumonia, hospitalization, and death.6 Compared to children, adults hospitalized for RSV are at a higher risk of severe complications, require more costly treatments, have a higher fatality rate, and the true number of RSV-related cases is likely underestimated due to lack of routine testing.7,8,9,10 References: 1 Horn et al, “Characteristics Associated with the Presence of One or More Risk Factors for Severe Respiratory Syncytial Virus Disease among Adults in the United States”, poster presented at ID Week 2024 [available on demand: P691 - DV-009542.pdf] 2 McLaughlin JM, et al. Rates of Medically Attended RSV Among US Adults: A Systematic Review and Meta-analysis. Page 17 Supplementary Data. Open Forum Infect Dis. 2022 Jun 17;9(7):ofac300. doi: 10.1093/ofid/ofac300. PMID: 35873302; PMCID: PMC9301578. 3 Clinicaltrials.gov. A Study on the Immune Response and Safety of Vaccine Against Respiratory Syncytial Virus (RSV) Given to Adults 18 to 49 Years of Age at Increased Risk for Respiratory Syncytial Virus Disease, Compared to Older Adults 60 Years of Age and Above. Available at: https://clinicaltrials.gov/study/NCT06389487. Last accessed: March 2026. 4 Clinicaltrials.gov. Efficacy Study of GSK's Investigational Respiratory Syncytial Virus (RSV) Vaccine in Adults Aged 60 Years and Above. Available at: https://clinicaltrials.gov/study/NCT04886596. Last accessed: March 2026. 5 National Institute of Allergy and Infectious Diseases, Respiratory Syncytial Virus (RSV). Available at: https://www-niaid-nih-gov.libproxy1.nus.edu.sg/diseases-conditions/respiratory-syncytial-virus-rsv. Last accessed: March 2026. 6 Falsey, A, R et al. Respiratory syncytial virus infection in elderly and high-risk adults, in New Engl J Med 2005; 352:1749-59. doi: 10.1056/NEJMoa043951. 7 Alfano F, et al. Respiratory Syncytial Virus Infection in Older Adults: An Update. Drugs Aging. 2014;41:487–505. 8 Niekler P, et al. Hospitalizations due to respiratory syncytial virus (RSV) infections in Germany: a nationwide clinical and direct cost data analysis (2010–2019). Infection. 2024;52(5):1715–1724. 9 Günen H, et al. Key Challenges to Understanding the Burden of Respiratory Syncytial Virus in Older Adults in Southeast Asia, the Middle East, and North Africa: An Expert Perspective. Adv Ther. 2024;41(11):4312–4334. 10 Grace M, et al. Economic burden of respiratory syncytial virus infection in adults: a systematic literature review. J Med Econ. 2023;26(1):742–759. The content above comes from the network. if any infringement, please contact us to modify.

The US FDA has approved an expanded age indication for Arexvy (respiratory syncytial virus vaccine, adjuvanted), GSK’s recombinant protein-based RSV vaccine, extending its use to adults aged 18 to 49 years at increased risk for lower respiratory tract disease caused by RSV. The decision makes Arexvy the third RSV vaccine to receive US FDA approval for at-risk adults under 50, following earlier label expansions for Pfizer’s Abrysvo in October 2024 and Moderna’s mRESVIA in 2025. Arexvy was previously approved in the US for adults aged 60 and older, and for those aged 50 to 59 at increased risk. An estimated 21 million US adults under 50 have at least one risk factor for severe RSV infection, the company said. The expanded indication covers adults aged 18 to 49 with chronic conditions that elevate RSV risk, including cardiopulmonary, kidney, and metabolic diseases such as diabetes and obesity. The vaccine is not approved for use in pregnant individuals. Arexvy contains a recombinant RSV glycoprotein F stabilized in the prefusion conformation (RSVPreF3), combined with GSK’s proprietary AS01E adjuvant system. It is administered as a single dose. The vaccine is now approved for adults 18 and older in the European Economic Area and across more than 60 countries for various adult age groups. The FDA’s decision was supported by data from a Phase IIIb open-label trial (NCT06389487) enrolling 1,458 participants across 52 sites in six countries. The study evaluated the immune response in 426 at-risk adults aged 18 to 49 compared with 429 adults aged 60 and above after a single dose. Primary endpoints were RSV-A and RSV-B neutralization titres at one month post-vaccination. The trial met its non-inferiority endpoints, demonstrating that the immune response in the younger at-risk cohort was non-inferior to that observed in older adults. Vaccine efficacy against RSV-associated lower respiratory tract disease had been established in the earlier Phase III trial (NCT04886596), which enrolled over 26,000 adults aged 60 and above. The safety profile in the expanded population was consistent with the broader Phase III programme, with injection site pain, fatigue, myalgia, headache, and arthralgia the most commonly reported adverse events. The approval places Arexvy alongside two other vaccines now available for younger at-risk adults, forming a competitive landscape that includes protein subunit, mRNA, and bivalent approaches. Pfizer’s Abrysvo, a non-adjuvanted bivalent prefusion F protein vaccine, received its 18-to-59 expansion in October 2024. Moderna’s mRESVIA, the only mRNA-based RSV vaccine, also gained approval for adults 18 to 59 at increased risk in 2025. All three approvals in younger adults relied on immunobridging strategies rather than direct efficacy endpoints in the target population. RSV accounts for approximately 17,000 hospitalisations, 277,000 emergency department visits, and nearly two million outpatient visits annually among US adults aged 18 to 49, with most hospitalisations occurring in those with chronic medical conditions. Prior to these vaccine approvals, no specific prophylactic or therapeutic intervention existed for RSV prevention in this age group. GSK continues to pursue regulatory submissions globally, and the company is conducting additional studies, including a Phase III trial in Chinese adults aged 18 to 59 at increased risk. Your email address will not be published. Required fields are marked * Comment * Name * Email * Website