FDA Expands Moderna’s RSV Vaccine Use to At-Risk Adults Aged 18–59

The U.S. Food and Drug Administration (FDA) has expanded the use of Moderna’s (NASDAQ:MRNA) RSV vaccine, mRESVIA, to adults aged 18 to 59 who are at increased risk of respiratory syncytial virus (RSV) disease. This marks the first non-COVID-19 mRNA vaccine approved in the U.S. and Moderna’s second marketed product. The shot was previously authorized for adults aged 60 and older.

Although the FDA approval is a critical milestone, the vaccine still requires a recommendation from the Centers for Disease Control and Prevention (CDC) before it becomes available to the newly approved age group. The CDC currently recommends RSV vaccination for adults 75+, and for those aged 60–74 at increased risk. In April, a CDC advisory panel supported expanding vaccine recommendations to at-risk adults aged 50–59.

mRESVIA’s broader approval is based on a late-stage trial showing strong immune responses in adults 18–59 with underlying health conditions. The vaccine was well-tolerated with no reported safety concerns. The FDA had approved it for older adults last year with an efficacy label of 79%, though Moderna’s trial showed 83.7% effectiveness.

Other approved RSV vaccines, including Pfizer’s Abrysvo (NYSE:PFE) and GSK’s Arexvy, are primarily authorized for those 60 and older, though both are also now approved for adults aged 50–59 at risk, with Abrysvo also covering ages 18–59.

Meanwhile, CDC vaccine policy may face challenges. Health Secretary Robert F. Kennedy Jr. recently replaced all 17 members of the CDC’s Advisory Committee on Immunization Practices, appointing some who have expressed anti-mRNA views. Experts warn this could erode public trust in vaccines.

RSV causes cold-like symptoms and can lead to serious illness, with 15,000–20,000 hospitalizations annually among adults aged 50–59.