16th February 2026
The recent decision by the U.S. Food and Drug Administration to decline review of an investigational mRNA-based influenza vaccine has reignited a long-standing debate about how innovation, regulation, and public health intersect. At issue is not vaccine safety, but whether regulatory standards are being applied in ways that could delay access to promising new technologies—and whether this signals a broader change in the United States' historical leadership in biomedical innovation.
What happened—and what did not
The FDA issued a Refusal-to-File letter to Moderna for its investigational seasonal influenza vaccine, mRNA-1010. A Refusal-to-File does not mean the vaccine is unsafe or ineffective; rather, it indicates that the agency will not begin formal review of the application as submitted. In this case, the FDA cited concerns about the design of the pivotal clinical trial, specifically the choice of comparator vaccine in older adults.
This distinction matters. The FDA did not halt trials, issue safety warnings, or reject mRNA technology as a platform. Instead, it determined that the application did not meet procedural requirements for review under current U.S. standards.
Why regulators disagree across regions
While the FDA paused review, regulators in Europe, Canada, and Australia accepted the same or similar data packages for evaluation. The European Medicines Agency, for example, agreed to review the application based on comparisons to licensed, commonly used flu vaccines.
This divergence reflects different regulatory philosophies rather than conflicting scientific evidence. In the United States, high-dose or adjuvanted influenza vaccines are often considered the preferred standard of care for adults aged 65 and older. The FDA therefore expects new vaccines targeting this population to demonstrate benefit against those enhanced comparators. In much of Europe, by contrast, standard-dose vaccines remain widely used in older adults, making them an acceptable benchmark for regulatory evaluation.
Both approaches are scientifically defensible. However, they ask different questions: the U.S. framework emphasizes superiority to the best available option, while the European framework emphasizes demonstrated benefit relative to real-world practice.
The potential public-health implications
Seasonal influenza causes substantial morbidity and mortality every year, particularly among older adults. mRNA-based flu vaccines are of interest because they may allow faster strain updates and potentially better immune matching than traditional manufacturing methods.
If these advantages translate into improved real-world effectiveness—a question that can only be answered over time—earlier access could reduce hospitalizations and deaths. Conversely, delayed access represents a missed opportunity rather than proven harm. At present, there is no evidence that the FDA's decision will directly result in excess deaths, but public-health experts note that delayed adoption of improved interventions can carry long-term consequences at the population level.
Does this signal a shift in U.S. leadership?
For decades, the United States has been viewed as the global leader in biomedical research, regulatory science, and vaccine innovation. The FDA has often been the first major regulator to approve novel technologies, setting benchmarks later adopted elsewhere.
This episode raises the question of whether that pattern is changing. If next-generation vaccines are routinely approved first in Europe, Canada, or Australia, the United States could transition from being a first adopter to a fast follower—or, in some cases, a laggard.
Such a shift would matter not only for influenza but for future vaccines against respiratory viruses and pandemic threats. Regulatory unpredictability can influence where companies invest, where trials are conducted, and which populations gain early access to innovation.
A balanced assessment
It would be inaccurate to claim that the FDA has become "anti-vaccine" or hostile to mRNA technology. At the same time, it would be naïve to dismiss concerns from researchers and industry about the cumulative impact of stricter, less harmonized regulatory expectations.
The core tension is not political but structural: how to balance rigorous standards with timely access, and how to align regulatory expectations across countries in an era of globalized science.
Conclusion
The FDA's refusal to review an mRNA influenza vaccine application does not represent a rejection of vaccines or a definitive retreat from science. However, it does highlight a growing divergence between the United States and peer regulators in how innovation is evaluated. If this divergence persists, the U.S. risks slower access to next-generation vaccines and a gradual erosion of its long-standing leadership in this field.
The challenge ahead is not choosing between safety and speed, but ensuring that regulatory rigor does not unintentionally become a barrier to progress—especially when other scientifically credible systems are moving forward.
The Moderna press release 10 February 2026
Moderna Receives Refusal-to-File Letter from the U.S. Food and Drug Administration for Its Investigational Seasonal Influenza Vaccine, mRNA-1010
Refusal to review the submission is inconsistent with feedback at pre-Phase 3 and pre-submission consultations; Moderna has requested a Type A meeting to understand the path forward
mRNA-1010 has been submitted and accepted for review in the EU, Canada and Australia
Company does not expect any impact on its 2026 financial guidance
CAMBRIDGE, MA / ACCESS Newswire / February 10, 2026 / Moderna, Inc. (NASDAQ:MRNA) today announced the U.S. Food and Drug Administration's (FDA) Center for Biologics Evaluation and Research (CBER) has notified the Company that it will not initiate a review of the biologics license application (BLA) for its investigational influenza vaccine, mRNA-1010, and has issued a Refusal-to-File (RTF) letter. Moderna had exercised a Priority Review Voucher to facilitate a timely review of the application.
CBER's RTF letter, signed by Center Director Vinayak Prasad, MD, MPH, identified the choice of a licensed standard-dose seasonal influenza vaccine comparator as the sole reason for the refusal to initiate the review of Moderna's application. Specifically, the letter cited the lack of an "adequate and well-controlled" study with a comparator arm that "does not reflect the best-available standard of care." Neither the relevant regulation, 21 C.F.R. § 314.126 (Adequate and well-controlled studies), nor the FDA's guidance for industry on seasonal influenza vaccines contain any reference to the use of a comparator reflecting the "best-available standard of care." The letter did not identify any specific safety or efficacy concerns regarding mRNA-1010.
The letter is inconsistent with previous written communications from CBER to Moderna. In April 2024, Moderna submitted the Phase 3 study protocol to CBER for review during a pre-Phase 3 consultation. CBER provided written guidance noting that "while we agree it would be acceptable to use a licensed standard dose influenza vaccine as the comparator in your Phase 3 study, we recommend you use a vaccine preferentially recommended for use in older adults by the ACIP (i.e., Fluzone HD, Fluad or Flublok) for participants >65 years of age in the study. Data on comparative efficacy of your vaccine against an influenza vaccine preferentially recommended for use in the >65 years age group may help inform ACIP's recommendation for the use of your vaccine in the older adult population. If you proceed with using a standard dose influenza vaccine comparator in participants ≥65 years of age, we agree with your plan to include statements in the Informed Consent Form." CBER did not raise any objections or clinical hold comments about the adequacy of the Phase 3 trial after the submission of the protocol in April 2024 or at any time before the initiation of the study in September 2024.
In August of 2025, following the successful completion of the Phase 3 efficacy trial in which mRNA-1010 met all agreed upon pre-specified primary endpoints, Moderna held a pre-submission meeting with CBER. In its written feedback, CBER requested that supportive analyses on the comparator be included in the submission and indicated that the data would be a "significant issue during review of your BLA." Moderna provided the additional analyses requested by CBER in its submission, including data from a separate Phase 3 trial (P303 Part C) comparing mRNA-1010 against a licensed high-dose influenza vaccine. At no time in the pre-submission written feedback or meeting did CBER indicate that it would refuse to review the file.
"This decision by CBER, which did not identify any safety or efficacy concerns with our product, does not further our shared goal of enhancing America's leadership in developing innovative medicines," said Stephane Bancel, Chief Executive Officer of Moderna. "It should not be controversial to conduct a comprehensive review of a flu vaccine submission that uses an FDA-approved vaccine as a comparator in a study that was discussed and agreed on with CBER prior to starting. We look forward to engaging with CBER to understand the path forward as quickly as possible so that America's seniors, and those with underlying conditions, continue to have access to American-made innovations."
Moderna has requested a Type A meeting with CBER to understand the basis for the RTF letter. In the interest of transparency, the Company has posted the full letter on its website, linked here.
mRNA-1010 has been accepted for review in the EU, Canada and Australia. Submissions in additional countries are planned for 2026. Moderna expects the earliest potential approvals for mRNA-1010 to begin in late 2026 or early 2027, subject to those ongoing regulatory reviews.
The Company does not expect an impact to its 2026 financial guidance based on the RTF from CBER.
About Moderna's mRNA-1010 Submission
Moderna's mRNA-1010 BLA submission includes two positive Phase 3 studies that enrolled a total of 43,808 participants and met all pre-specified primary endpoints. Both Phase 3 designs were reviewed by FDA prior to study initiation. P303 Part C was a safety and immunogenicity study that compared mRNA-1010 against a high-dose comparator in adults aged 65 years or older. P304 was a safety and relative efficacy study that compared mRNA-1010 against a licensed standard-dose comparator in adults aged 50 years and older. In both Phase 3 studies, the primary endpoints showed statistical superiority of mRNA-1010 compared with the respective comparators. P303 has been published in a peer-reviewed publication and P304 has been submitted for publication.
The trial design for the P304 efficacy study, showing superiority over a licensed standard-dose influenza vaccine, is similar to that used to approve two licensed influenza vaccines that are preferentially recommended for adults aged 65 years or older in the U.S. Those approved products demonstrated a similar degree of statistically superior relative efficacy over a standard-dose influenza vaccine comparator as was achieved by mRNA-1010 in P304.[1][2] One of these products used the same licensed standard-dose comparator (Fluarix®), which is licensed in the U.S. for all adults, including for adults aged 65 years or older. Approximately 2 million U.S. adults aged 65 years or older received a standard-dose influenza vaccine in the most recent influenza season.[3][4]
Many countries outside the U.S. do not preferentially recommend high-dose influenza vaccines over standard-dose influenza vaccines for adults aged 65 or older.[5]
About Moderna
Moderna is a pioneer and leader in the field of mRNA medicine. Through the advancement of its technology platform, Moderna is reimagining how medicines are made to transform how we treat and prevent diseases. Since its founding, Moderna's mRNA platform has enabled the development of vaccines and therapeutics across infectious diseases, cancer, rare diseases and more.
With a global team and a unique culture, driven by the company's values and mindsets, Moderna's mission is to deliver the greatest possible impact to people through mRNA medicines. For more information about Moderna, please visit modernatx.com and connect with us on X, Facebook, Instagram, YouTube and LinkedIn.
15 February 2026
Jonathan Cohn in his Substack newsletter The Breakdown commented.
This Is What Destroying the Vaccine Market Looks Like
A shocking move by RFK Jr.'s team has the industry spooked—for good reason.
A potentially groundbreaking vaccine for seasonal flu that the Massachusetts-based company had developed would not be getting approval from regulators. In fact, it wasn't even getting formal consideration, Moderna announced in a Tuesday press release, because officials were refusing to accept the application.
This is not the type of development you would normally expect a pharmaceutical company to broadcast. But that's because there’s nothing normal about the way the federal government is behaving in this saga—or, for that matter, how the government has been behaving ever since President Donald Trump put anti-vaccination crusader Robert F. Kennedy Jr. in charge of America’s public health.
Moderna’s flu shot, which uses mRNA technology made famous during the COVID-19 pandemic, is the product of a lengthy research and development process that goes back years. Along the way, Moderna scientists consulted directly with officials at the Food and Drug Administration, the agency inside of Kennedy’s department (Health and Human Services) that is responsible for reviewing and approving vaccines.
Read it in full at https://www.thebulwark.com/p/this-is-what-destroying-the-vaccine-market-looks-like-moderna-flu-prasad-fda