FDA expands approval of Moderna's RSV vaccine to some adults under age 60

The FDA has expanded approval of Moderna's mRESVIA RSV vaccine to include adults under 60 at increased risk, based on clinical trial data showing boosted immune responses in younger adults; however, CDC recommendations, which currently only cover those 75 and older and those 60 and over at increased risk, are needed for the new age group to be eligible, and recent changes to the CDC's vaccine advisory committee and skepticism towards mRNA technology among new members introduce uncertainty regarding future recommendations, particularly given lagging RSV vaccination rates.

Analysis

The U.S. Food and Drug Administration's expanded approval of Moderna's mRESVIA RSV vaccine to include adults under the age of 60 at increased risk marks a regulatory advancement, based on late-stage clinical trial data demonstrating enhanced immune responses in this demographic, which Moderna estimates includes over one-third of adults aged 18-59 with at least one underlying condition. However, the commercial impact of this expanded approval is significantly contingent on subsequent recommendations from the Centers for Disease Control and Prevention (CDC). Currently, CDC guidelines limit RSV vaccination to those aged 75 and older, and those 60 and over at increased risk. The path to broader eligibility faces considerable uncertainty due to recent structural changes within the CDC's independent vaccine advisory committee, where all 17 sitting members were replaced by eight new appointees, some of whom have reportedly expressed skepticism regarding mRNA technology, the basis for mRESVIA. Furthermore, Health and Human Services Secretary Robert F. Kennedy Jr., who is currently making final CDC recommendations, previously chose not to adopt a committee recommendation to expand RSV vaccination to at-risk individuals aged 50-59. The reconstituted committee is scheduled to re-evaluate RSV vaccine recommendations between June 25 and June 27. Compounding these regulatory hurdles, existing RSV vaccine uptake is notably low—as of April 26, only 47.5% of adults aged 75 and older and 38.1% of high-risk adults aged 60 to 74 reported receiving an RSV vaccine—indicating a persistent market penetration challenge.

Key Decisions for Investors

• Acknowledge the FDA's expanded approval for mRESVIA as a positive development for Moderna's potential addressable market, but weigh this against the substantial uncertainty surrounding necessary CDC recommendations.
• Closely monitor the proceedings and outcomes of the CDC's vaccine advisory committee meeting scheduled for June 25-27, paying particular attention to the new committee's stance on mRNA-based vaccines and the scope of any RSV vaccine recommendations, as these will be critical determinants for mRESVIA's market expansion.
• Factor in the persistently low uptake rates for existing RSV vaccine recommendations as a realistic constraint on potential revenue generation, even if broader CDC guidelines are eventually issued for mRESVIA.