In a significant regulatory development, vaccine manufacturer Moderna has announced that the U.S. Food and Drug Administration has declined to review its application for the company's first mRNA-based influenza vaccine. This decision comes amid broader FDA calls for reconsideration of approval procedures for certain vaccines, including influenza shots, under proposed federal policy changes that have raised concerns among public health professionals.
Clinical Trial Design Concerns
Moderna revealed it received a letter from Vinay Prasad, the FDA's top vaccine regulator, indicating that the clinical trial for the flu vaccine was not considered "adequate and well-controlled." The agency also noted the vaccine was not tested against what it considers the best available vaccine on the market.
The pharmaceutical company had compared its new mRNA vaccine to Fluarix, a vaccine from GSK that has already received FDA approval. Moderna expressed disappointment with the decision, stating the rejection was "inconsistent with previous written communications" with the FDA's Center for Biologics Evaluation and Research, the branch responsible for regulating biological products including vaccines.
No Safety or Efficacy Issues Identified
Moderna CEO Stephane Bancel emphasized that the FDA's decision "did not identify any safety or efficacy concerns with our product" and argued that the move "does not further our shared goal of enhancing America's leadership in developing innovative medicines."
Bancel further stated, "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."
Regulatory Requirements Not Met
According to Moderna, the company received a Refusal-to-File letter stating that its vaccine application did not meet the requirements for a substantive review. The manufacturer has requested a meeting with FDA officials to discuss the decision and potential paths forward.
Notably, the FDA letter did not raise any specific safety or efficacy concerns about the mRNA vaccine technology itself. Moderna pointed out that the same vaccine application has been accepted for review by regulatory agencies in Canada, Australia, and the European Union.
Political and Historical Context
The decision occurs against a backdrop of changing vaccine policy landscapes. Former U.S. President Donald Trump, who during his first administration called mRNA technology a "modern-day miracle," appointed Robert F. Kennedy Jr. as his health chief during his second term. Kennedy has long been known as a vaccine skeptic and has spent recent years reshaping the image of federal health agencies.
Kennedy's views have generated increased skepticism about vaccine safety and efficacy, and he has implemented cuts to federal research grants for mRNA development. This political environment adds complexity to the regulatory landscape for new vaccine technologies.
mRNA Technology Background
The mRNA technology at the center of this controversy was instrumental during the COVID-19 pandemic, enabling the rapid development of vaccines against the virus. COVID-19 vaccines utilizing mRNA technology are considered safe and effective by global health authorities and have demonstrated significant protection against severe infection outcomes.
Moderna's attempt to apply this successful technology platform to seasonal influenza represents a significant step in vaccine innovation, though the FDA's current decision creates a substantial hurdle for this particular application.
