FDA Reverses Stance, Initiates Formal Review for Moderna Flu Vaccine

The FDA reversed its previous stance and will now initiate a formal review of Moderna’s biologics license application (BLA) for mRNA-1010, its investigational seasonal influenza vaccine, according to a Moderna news release.¹

“We appreciate the FDA's engagement in a constructive Type A meeting and its agreement to advance our application for review,” Moderna CEO Stéphane Bancel said in the news release. “Pending FDA approval, we look forward to making our flu vaccine available later this year so that America's seniors have access to a new option to protect themselves against flu.”

As Bancel mentioned, this decision follows a constructive Type A meeting between Moderna and the FDA’s Center for Biologics Evaluation and Research (CBER), resulting in a revised regulatory approach that could see the vaccine available for the 2026-2027 flu season. For pharmacists who are central to vaccine administration and inventory management, the FDA assigned a Prescription Drug User Fee Act goal date of August 5, 2026, with potential availability expected shortly after.²

The path to this review was marked by a rare regulatory hurdle when the FDA initially issued a refusal-to-file letter to Moderna.^3,4

READ MORE: Q&A: Medical Communities United on Support for COVID-19, mRNA Vaccines

The agency’s primary objection centered on the design of Moderna’s clinical trials, specifically the choice of a comparator vaccine for participants aged 65 years and older.³ CBER officials argued that using a standard-dose seasonal flu vaccine as a control arm failed to reflect the best-available standard of care for seniors, who are preferentially recommended to receive high-dose or adjuvanted vaccines.

This disagreement led to a public exchange, with FDA Commissioner Marty Makary, MD, MPH, suggesting the trial design may have put seniors at risk, while Moderna leadership expressed shock, maintaining that the FDA had cleared the trial design 18 months prior.^2,3

The current resolution involves a bifurcated regulatory strategy designed to address these clinical concerns while advancing the technology.^1,4 Under the new agreement, Moderna is seeking full approval for adults aged 50 to 64 years as well as accelerated approval for those 65 years and older.^1,2

To satisfy the requirements for the older demographic, Moderna has committed to post-marketing efforts where they’ll conduct an additional study in seniors to confirm the vaccine’s effectiveness against high-dose alternatives. This compromise allows the FDA to maintain its high standards for licensure, providing a pathway for what could be the first mRNA-based influenza vaccine in the US.^1,2,4

This regulatory volatility comes at a time of broader shifts within federal health agencies, with some observers noting increased skepticism toward mRNA technology under current leadership. The initial rejection caused significant market fluctuations, with Moderna shares dropping 12% before rebounding by 6% following the news of the FDA’s reversal.²

Beyond the financial implications, the back-and-forth highlights a changing landscape for vaccine oversight that pharmacists must navigate as they plan for future immunization schedules and respiratory virus seasons.^2,3

Although the FDA's initial letter did not identify specific safety or efficacy concerns with mRNA-1010 itself, the emphasis on trial comparators underscores a rigorous focus on how new vaccines measure up against current preferential recommendations.

Pending the results of the FDA's review, Moderna expects the vaccine to provide a new option for protecting American seniors and those with underlying conditions.^1,3 As the PDUFA date approaches, the pharmacy profession will be watching closely to see if this technology finally joins the annual fold against seasonal influenza during the winter months.^2,4

“Discussions with the company led to a revised regulatory approach and an amended application, which FDA accepted,” said Andrew Nixon, a spokesperson for the US Department of Health and Human Services, in a CNN article.⁴ “FDA will maintain its high standards during review and potential licensure stages as it does with all products.”

READ MORE: Immunization Resource Center

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REFERENCES

1. Moderna announces the U.S. Food and Drug Administration will initiate the review of Its investigational seasonal influenza vaccine submission. News Release. Moderna. February 18, 2026. Accessed February 19, 2026. https://feeds.issuerdirect.com/news-release.html?newsid=8923338804483797&symbol=MRNA

2. Sunny ME, Erman M. US FDA reverses course, will review Moderna’s flu vaccine application. Reuters. February 18, 2026. Accessed February 19, 2026. https://www.reuters.com/business/healthcare-pharmaceuticals/us-fda-initiate-review-modernas-influenza-vaccine-2026-02-18/

3. Nowosielski B. FDA refuses to file Moderna’s seasonal influenza vaccine application. Drug Topics. February 13, 2026. Accessed February 19, 2026. https://www.drugtopics.com/view/fda-refuses-to-file-moderna-s-seasonal-influenza-vaccine-application

4. McPhillips D. FDA reverses course and will review Moderna’s mRNA flu shot, company says. CNN Health. Published February 18, 2026. Accessed February 19, 2026. https://www.cnn.com/2026/02/18/health/fda-moderna-mrna-flu-vaccine-reversal