Health Secretary Robert F. Kennedy Jr. said Tuesday that the government is pulling $500 million in funding to develop new mRNA vaccines in order to focus on “safer, broader vaccine platforms.”

Why it matters: Among the 22 contracts the Trump administration said it is winding down is a Biomedical Advanced Research and Development Authority award to Moderna to develop a new line of defense against H5N1 bird flu.

The administration said is also rejecting or canceling proposals from Pfizer and Sanofi Pasteur that were part of a BARDA rapid response partnership.

What they’re saying: Kennedy said data showed the vaccines in question “fail to protect effectively against upper respiratory infections like COVID and flu.”

“We’re shifting that funding toward safer, broader vaccine platforms that remain effective even as viruses mutate,” he said.

HHS said some final-stage contracts to produce vaccines for targets like pandemic bird flu will be allowed to run their course to preserve taxpayer investment, but added no new mRNA-based projects will be initiated.

Yes, but: Infectious disease specialists said the move applies the unrealistic standard of blocking all infections when the actual goal is to reduce serious illness and death.

“No vaccine for respiratory viruses — COVID, flu, RSV — provides durable sterilizing immunity. That was never the standard and shouldn’t be the expectation,” Stanford associate professor Jake Scott wrote on X.

“Ending BARDA’s investment in mRNA technology creates a national security vulnerability,” said Chris Meekins, a Raymond James analyst and an HHS strategic preparedness official in the first Trump administration. 

“These tools serve as a deterrent to prevent other nations from using certain biological agents. The speed of the technology to create new biodefense capabilities is a national security asset,” Meekins said. 

Moderna, in a statement, said it wasn’t aware of any new contract cancellations by BARDA and that its pandemic flu contract was canceled in May, leaving it with no active collaborations with the agency.

Catch up quick: The contract cancellations mark the latest step in Kennedy’s overhaul of federal vaccine policies. He most recently proposed overhauling vaccine makers’ federal liability protections. Major medical organizations last week reported being excluded from working groups that advise the CDC’s Advisory Committee on Immunization Practices.

Kennedy has repeatedly pushed the debunked idea that vaccines cause autism and in the past was involved in litigation over patient injury claims.

Some conservative-led states have targeted mRNA vaccines amid ongoing suspicion of public health officials and the tools they used to fight the COVID-19 pandemic.

The story has been updated with comment from Moderna.