Moderna’s New Flu Shot Hits a Roadblock

The U.S. Food and Drug Administration (FDA) has decided not to review Moderna’s mRNA flu vaccine, despite the company’s extensive investment in testing and development.

Why the FDA Stopped the Review

• Regulator’s Concern: Dr. Vinay Prasad, chief vaccine regulator at the FDA, questioned the trial’s comparison arm.
• Control Vaccine Issue: The study used Fluarix Quadrivalent from GSK as the control, which the FDA does not consider the best market option.

Study Details

• Participants: 41,000 adults aged 50 and older.
• Outcome Claim: Moderna reported that its vaccine outperformed the GSK product in the trial.

Company’s Response

• Stephen Hoge, President of Moderna:
• Emphasized that the new shot is tailored to a specific country rather than covering an entire hemisphere.
• Highlighted prior FDA support for the study plan.
• Expressed confusion and surprise at the sudden refusal to begin review, stating that the company is trying to understand what changed.

Official Silence

• A spokesperson for the Department of Health and Human Services (overseeing the FDA) declined to comment on individual applications.
• The agency reiterated that it does not discuss communications with specific applicants.

Implications

This decision underscores the growing tension between federal health agencies and vaccine developers, raising questions about regulatory standards and approval pathways.