Moderna's RSV Vaccine, mRESVIA, Approved by U.S. FDA for At-Risk Adults 18–59

Moderna, Inc., headquartered in Cambridge, Massachusetts, has announced an expansion in the approval of its RSV vaccine, mRESVIA® (mRNA-1345), by the U.S. Food and Drug Administration (FDA). Initially approved for adults aged 60 years and older in May 2024, mRESVIA is now also authorized for individuals aged 18 to 59 who are at heightened risk for serious illness due to RSV. This development marks a significant milestone in broadening protection against RSV-related lower respiratory tract disease (LRTD) among more vulnerable demographics.

The respiratory syncytial virus (RSV) is a well-known threat, especially to infants and the elderly. However, adults aged 18 to 59 who have chronic health conditions are equally susceptible to severe RSV complications. Statistics indicate that over one-third of this younger adult population has at least one chronic condition, increasing their risk of severe RSV disease. The hospitalization and disease burden in these individuals is comparable to, and can sometimes exceed, that observed in older adults.

Moderna's expanded approval of mRESVIA is backed by extensive clinical trials. A pivotal Phase 3 study, identified as NCT06067230, evaluated the safety and immunogenicity of the vaccine in adults aged 18 to 59 with existing health conditions. This study demonstrated that immune responses to RSV subtypes RSV-A and RSV-B met predefined non-inferiority immunobridging criteria, which were previously established for adults 60 years and older. The trials showed uniform levels of neutralizing antibodies across age subgroups, specifically those aged 18 to 49 and 50 to 59, affirming the vaccine's consistent efficacy in younger adults at risk. These results were shared at the CDC's Advisory Committee on Immunization Practices meeting in April 2025 and were published in Clinical Infectious Diseases.

In terms of safety, mRESVIA was generally well-tolerated by participants. The most commonly reported adverse reactions included pain at the injection site, fatigue, headache, muscle pain, and joint pain. As the respiratory virus season approaches, Moderna plans to make mRESVIA available for both younger adults at increased risk and older adults in the U.S. for the 2025-2026 season.

mRESVIA® is an innovative RSV vaccine comprising an mRNA sequence that encodes a stabilized prefusion F glycoprotein, a crucial component for RSV infection. This prefusion conformation is a key target for potent neutralizing antibodies and is preserved across RSV-A and RSV-B subtypes. The vaccine employs the same lipid nanoparticle technology used in Moderna’s COVID-19 vaccines, demonstrating the versatility and efficacy of mRNA-based vaccines.

Moderna has established itself as a pioneer in mRNA medicine, revolutionizing the development and manufacturing of medical treatments. The company’s advanced mRNA platform has facilitated the creation of therapeutics and vaccines for various medical needs, including infectious, autoimmune, and rare diseases. Moderna’s global team, driven by a unique culture and core values, is committed to leveraging mRNA technology to transform healthcare and enhance human health. Through innovation in science and technology, Moderna aims to achieve substantial impacts in the field of medicine.

The approval of mRESVIA for expanded use reflects Moderna's ongoing commitment to addressing unmet medical needs and improving public health outcomes. As the company continues to innovate and expand its product offerings, it remains dedicated to providing effective solutions for preventing and treating diseases worldwide.