FDA advisors unanimously vote to approve Moderna’s mRNA after agency drama

FDA advisory committee members unanimously voted 9–0 in favor of approving Moderna’s mRNA seasonal flu vaccine, overcoming earlier agency resistance and controversy. This decision is a key step toward potentially adding a new, more effective flu vaccine to the market, which could impact public health strategies for the upcoming flu season.

The FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) reviewed data showing Moderna’s vaccine, dubbed mRNA-1010 or mFlusiva, demonstrated approximately 27% greater effectiveness against seasonal flu in adults over 50, based on a Phase 3 trial involving over 40,000 participants. Additional data from a smaller trial indicated stronger immune responses in those aged 65 and older compared to high-dose flu vaccines. The safety profile was generally positive, with no significant safety concerns raised during the review. The committee’s support marks a significant turnaround after a February controversy when an FDA official, Vinay Prasad, refused to review the vaccine, citing inadequate trial design. This decision was later reversed following public outcry, and the vaccine’s review proceeded. Moderna expressed satisfaction with the outcome, emphasizing the potential of mRNA technology to improve flu prevention and pandemic preparedness. The FDA is expected to make a final decision by August 5, after which the vaccine would need CDC approval for widespread use.

Implications of the Unanimous VRBPAC Vote for Moderna’s Flu Vaccine

This approval process is a critical step toward introducing a potentially more effective flu vaccine that leverages mRNA technology, which has been proven successful during the COVID-19 pandemic. If approved, the vaccine could enhance seasonal flu prevention, especially among older adults, and demonstrate the versatility of mRNA platforms beyond COVID-19. The decision also reflects a possible shift in FDA review practices following recent internal disputes, highlighting the importance of independent advisory committees in vaccine approval.

Background on the FDA’s Vaccine Review Controversies

In February, a high-profile dispute arose when FDA official Vinay Prasad refused to review Moderna’s vaccine application, claiming the trial data was not adequate because it did not compare efficacy directly to a high-dose vaccine in older adults. This decision was widely criticized, leading to a reversal by the FDA and an eventual review of the vaccine. Prasad’s stance and subsequent removal from the agency followed a series of controversial decisions, including the rejection of a gene therapy for Huntington’s disease. The episode underscored tensions within the FDA over vaccine approval processes and the role of independent advisory committees. Moderna’s vaccine development is part of a broader effort to modernize flu vaccines using mRNA technology, which has shown promise in recent years.

“The studies presented today were very well conducted, with clear and robust results demonstrating additional efficacy.”

— an anonymous researcher

Remaining Questions About Moderna’s Flu Vaccine Approval

While the VRBPAC vote was unanimous, the final decision by the FDA is still pending, expected by August 5. It remains unclear whether the FDA will approve the vaccine as recommended, especially given ongoing political and legal challenges affecting vaccine policy and CDC advisory committee processes. Additionally, the status of CDC approval, which is necessary for widespread use and insurance coverage, is uncertain due to the ongoing injunction affecting the CDC’s advisory committee.

Next Steps Toward Vaccine Deployment and Public Use

The FDA is scheduled to make its final decision by August 5. Following approval, Moderna aims to release the vaccine later this year, contingent on CDC endorsement. The CDC’s Advisory Committee on Immunization Practices (ACIP) would then review and recommend the vaccine for broad use, but recent legal challenges have temporarily impeded this process. The outcome of the legal disputes and subsequent CDC review will determine the vaccine’s availability and coverage in the upcoming flu season.

Key Questions

What is Moderna’s mRNA flu vaccine and how does it differ from traditional flu vaccines?

Moderna’s mRNA flu vaccine, called mRNA-1010 or mFlusiva, uses messenger RNA technology to instruct cells to produce antigens, triggering an immune response. Unlike traditional flu vaccines, which are made from inactivated viruses or viral proteins, mRNA vaccines can be developed more rapidly and may offer improved efficacy, especially in older populations.

Why was there controversy within the FDA regarding this vaccine?

In February, an FDA official refused to review Moderna’s application, claiming the trial data was insufficient because it did not compare efficacy directly to a high-dose vaccine in older adults. This decision was reversed after public outcry, but it caused significant internal and external controversy over the vaccine approval process.

What are the next steps before the vaccine can be widely used?

The FDA must issue a final approval decision by August 5. Subsequently, the CDC’s advisory committee will review and recommend the vaccine for broad use. Legal challenges and the current injunction affecting the CDC’s committee may delay or complicate this process.

How might this vaccine impact future flu prevention efforts?

If approved, the vaccine could provide a more effective and adaptable tool for seasonal flu prevention, especially for vulnerable populations. It also demonstrates the potential of mRNA technology to modernize vaccine development beyond COVID-19.

Source: Ars Technica