Vinay Prasad, who serves as the Trump administration’s chief vaccine regulator at the Food and Drug Administration, has unilaterally opted not to review Moderna’s mRNA influenza vaccine, despite objections from within the agency. According to reports by Stat News and The Wall Street Journal, Prasad overrode the decision of FDA scientists keen to initiate the review process.
Stat initially reported, citing anonymous FDA insiders, that a group of veteran scientists was poised to review Moderna’s vaccine. Notably, David Kaslow, a senior official responsible for vaccine reviews, drafted a memo protesting Prasad's decision. The memo supposedly provided a comprehensive rationale for pursuing the vaccine evaluation.
The Wall Street Journal corroborated this account with its sources. They revealed that a meeting took place in early January where FDA scientists extensively detailed their objections to Prasad’s plan to impede the review. Prasad, characterized as a politically appointed figure prone to controversy and linked to anti-vaccine views, was informed this was the inappropriate course of action.
The source of Prasad’s objection did not lie with Moderna's experimental mRNA vaccine itself but rather with the choice of a comparator vaccine used during a Phase 3 clinical trial. This trial involved nearly 41,000 adults aged 50 and above. Previously, the FDA had raised no issues during numerous reviews of Moderna's trial plans, prior to submission.
Moderna acknowledged that FDA scientists had recommended a different comparator for participants aged 65 and older—those eligible for a high-dose flu vaccine. However, they emphasized that the FDA had ultimately deemed Moderna’s strategy “acceptable.”