The FDA has expanded the approval of Moderna's RSV vaccine, mResvia, to include adults aged 18 to 59 who are at high risk of severe illness from respiratory syncytial virus (RSV).

Notably, mRESVIA is the first non-COVID-19 messenger RNA (mRNA) vaccine approved in the United States, having already been authorized for adults aged 60 and older.

This approval was based on a Phase 3 study that demonstrated significant immune responses and safety in the new age group.

The vaccine was generally well-tolerated, with common side effects including injection site pain, fatigue, headache, myalgia, and arthralgia.

However, for the vaccine to be administered to the newly approved age group, the U.S. Centers for Disease Control and Prevention (CDC) must still recommend it.

The Advisory Committee on Immunization Practices (ACIP) has made a recommendation, but it is pending approval from the currently vacant CDC director.

Without this CDC approval, health insurers are not obligated to cover the costs of the vaccine for the new age group.

RSV is known to cause cold-like symptoms and is a leading cause of pneumonia, with the CDC estimating 15,000 to 20,000 annual RSV-related hospitalizations in adults aged 50 to 59 in the U.S.

The approval comes amid challenges for Moderna, particularly skepticism towards its mRNA vaccine platform from some supporters of Health Secretary Robert F. Kennedy Jr.

Kennedy recently dismissed the entire ACIP to restore public confidence in vaccines and appointed new committee members, with a meeting scheduled for late June 2025.

Moderna CEO Stéphane Bancel emphasized the importance of this approval for adults with chronic conditions who are vulnerable to RSV.

Moderna is preparing to make mResvia available for the upcoming 2025-2026 respiratory virus season for both the newly approved age group and seniors.