Still, while Moderna largely stuck with its plan to use a standard dose for all participants, it altered its plans based on the feedback. Specifically, it added a comparison of a high-dose vaccine to some older participants and provided the FDA with an additional analysis.

This wasn’t enough for Prasad, who, according to the Journal’s sources, told FDA staff that he wants to send more such refusal letters that appear to blindside drug developers. The review staff apparently pushed back, noting that such moves break with the agency’s practices and could open it up to being sued. Prasad reportedly dismissed concern over possible litigation. Trump’s FDA Commissioner Marty Makary seemed similarly unconcerned, suggesting on Fox News that Moderna’s trial may be “unethical.”

A senior FDA official suggested to Stat, meanwhile, that the door might not be entirely closed for Moderna’s flu vaccine. The official said that the company could toss the data for the 65 and up participants and, perhaps, grovel.

“It is entirely feasible that if they come back, maybe even show some humility and say, ‘Yes, we didn’t follow your recommendation. Just take a look at the 50 to 65 group, where there’s a little more equipoise,’” the official told Stat. “Then the review team could say, ‘We’ll consider that cohort.’”

The Journal notes that Moderna is at least the ninth company to have received a surprise rejection from Prasad and his team. The unpredictability is raising fears about the industry’s ability to obtain investments and innovate.

Prasad, a blood cancer specialist who has no expertise or experience in vaccine regulation, is also facing internal problems at the agency. His management style has created an environment “rife with mistrust and paranoia,” according to Stat. The Journal reports that several complaints have been filed against him, including some involving sexual harassment, retaliation against subordinates, and verbally berating staff.