Former FDA Heads Warn on Prasad’s New Vaccine Policies

A dozen former FDA commissioners have issued an extraordinary public warning this week, arguing that sweeping internal directives proposed by CBER director Vinay Prasad would undermine evidence-based vaccine regulation and threaten public health. In a New England Journal of Medicine Perspective, the former officials said a memo circulated last week by Prasad represents a radical break from long-standing scientific standards that guide vaccine development and evaluation.

The memo, they wrote, “will upend core policies governing vaccine development and updates” and is being imposed “unilaterally,” without public consultation or adherence to federal rulemaking processes that ordinarily govern major regulatory changes. They also sounded alarms on “troubling changes” under FDA’s current leadership, including unusually high staff departures and indications that the agency may bypass scientific advisory committee reviews for key decisions.

According to the former commissioners, Prasad’s internal memo:

• Labels FDA scientists’ engagement with external experts about agency processes as “unethical” and “illegal.”
• Orders that scientific debate remain internal “until [issues] are ready to be made public.”
• Tells staff who disagree with the new framework to “submit your resignation letters.”
• Reinterprets existing evidence to argue that no immune surrogate markers — such as antibody levels — should support approvals of updated vaccines.

The commissioners said such messages suppress scientific discourse inside the agency and set a precedent in which dissent is treated as insubordination rather than part of normal scientific deliberation.

At the core of their critique is Prasad’s move to reject “immunobridging” — the long-standing method that allows vaccine makers to update products based on immune responses once a correlate of protection is established. The approach is essential for fast-moving respiratory pathogens like influenza and SARS-CoV-2, they said. Requiring randomized clinical trials for each updated vaccine strain would be “prohibitive,” delaying annual flu and COVID-19 updates and limiting competition, particularly among smaller biotech firms.

“This framework would impede the ability to update vaccines to keep up with evolving threats,” they wrote, adding that older adults and immunocompromised individuals would be most harmed.

Prasad’s memo also cites a retrospective reanalysis of unverified reports in the Vaccine Adverse Event Reporting System (VAERS) to conclude that Covid-19 vaccines caused the deaths of 10 children — a claim the former commissioners say is unsupported and breaks from established safety-surveillance science.

VAERS reports “cannot be used to determine causality,” they wrote, noting that previous FDA reviews of the same cases had reached different conclusions. No explanation was offered for the new assessment, they said, nor for how the analysis justifies a sweeping overhaul of vaccine approval standards across diseases.

Additionally, the former FDA leaders characterized Prasad’s policy changes as a threat to the FDA’s core identity as a science-driven, pluralistic institution. “Demands for ideological alignment as a condition of employment are irreconcilable with an agency whose strength is the pluralism of its expert views,” they wrote. Americans’ safety, they continued, “depends on… a culture in which evidence is reviewed openly and staff can surface concerns… without fear of reprisal.”

The authors urged the agency to adhere to statutory procedures — including public comment and advisory-committee review — before implementing any changes of this magnitude. “If the goal is to rebuild confidence,” they concluded, “the answer is not to toss aside the basic rules of science… but to insist on open deliberation, solid evidence, and procedures the public can see and trust.”