WASHINGTON (Diya TV) — A top Food and Drug Administration official overruled agency scientists and refused to accept Moderna’s application for a new influenza vaccine, according to three federal officials familiar with the decision reports StatNews.
The move by Vinay Prasad marks the latest sign of internal tension at the FDA over how the agency handles vaccine approvals. Career reviewers had prepared to begin evaluating the shot. Instead, the application stalled before the formal review process could start. The decision raises new questions about vaccine oversight at the FDA, especially as flu season remains a public health concern.
Moderna submitted an application seeking approval for a new influenza vaccine. A team of career scientists at the Food and Drug Administration had signaled that the submission met the basic requirements to move forward.
Three agency officials said staff members stood ready to begin a formal scientific review. They said the reviewers saw no procedural barriers that would prevent them from evaluating the data. However, Prasad declined to accept the application. That step effectively blocked the review from starting. The officials spoke on condition of anonymity because they were not authorized to discuss internal agency matters.
According to the officials, David Kaslow, who leads the FDA’s vaccine office, wrote a detailed memo supporting the review of Moderna’s flu shot. Kaslow’s memo reportedly explained why the agency should proceed with the evaluation. The document outlined the scientific and regulatory grounds for launching the review process.
Despite that recommendation, Prasad, who is the FDA’s Chief Medical and Scientific Officer, chose not to accept the application. The FDA has not publicly released the memo. The agency also has not issued a detailed explanation of the decision.
The rejection reflects what some insiders describe as tougher scrutiny of vaccines under the current leadership. Prasad has taken a more aggressive stance on vaccine oversight in recent months, according to current and former officials. Critics inside the agency say he has intervened in scientific decisions that staff traditionally handled.
The development comes as vaccine policy faces increased political pressure. Robert F. Kennedy Jr., the U.S. health secretary, has long expressed skepticism about certain vaccines. Public health experts have voiced concern that such views could influence federal health agencies. Officials said vaccine skepticism appears to have gained traction within parts of the FDA’s leadership.
Prasad and another senior official, Tracy Beth Høeg, have also taken control of vaccine surveillance activities, according to agency officials. Career civil servants traditionally managed those monitoring systems. They track vaccine safety and effectiveness after approval.
Some staff members worry that leadership changes could disrupt routine oversight. Others argue that stronger review standards protect public trust. The FDA plays a central role in reviewing and approving vaccines in the United States. Its decisions affect millions of Americans who rely on flu shots each year.
Influenza vaccines remain a key tool in preventing serious illness and hospitalizations. Each year, the Centers for Disease Control and Prevention recommends annual flu shots for most Americans. Moderna, best known for its COVID-19 vaccine, has invested heavily in expanding its mRNA technology into other vaccines, including flu. A delay in the FDA review could slow the company’s efforts to bring a new influenza vaccine to market.
Public health experts say transparency in vaccine approvals remains critical. Clear communication about why the FDA accepts or rejects applications helps maintain confidence in the system. For now, Moderna’s flu vaccine application remains in limbo. The FDA has not announced whether it will reconsider the decision.
