FILE PHOTO: A man casts a shadow as he walks toward the Hubert H. Humphrey Building, headquarters of the Department of Health and Human Services (HHS) in Washington, D.C., U.S., April 1, 2025. REUTERS/Kevin Lamarque/ File Photo

(Reuters) -Vaxart said on Wednesday it received an order to stop work on screening and enrollment for its COVID-19 mid-stage trial, joining multiple biotech companies that have lost government funding for their vaccine programs.

The drug developer said it will keep working on its oral COVID-19 vaccine by monitoring participants already in the trial, but it will stop new enrollment.

The order is part of the U.S. Department of Health and Human Services decision to wind down mRNA vaccine development activities under its biomedical research unit.

The unit, Biomedical Advanced Research and Development Authority, helps companies develop medical supplies to address public health threats, and had provided billions of dollars for development of vaccines during the COVID pandemic.

This is the latest development under U.S. Health Secretary Robert F. Kennedy Jr., a long-time vaccine skeptic who has been making sweeping changes to reshape vaccines, food and medicine policies.

Kennedy said the HHS is terminating these programs because data show these vaccines "fail to protect effectively against upper respiratory infections like COVID and flu," but did not offer scientific evidence.

Vaxart's project award was valued at up to $453 million, which included an upfront $65.7 million and up to $387.2 million in milestone payments.

The milestone payment was dependent on whether BARDA determines that the study may further proceed.

(Reporting by Christy Santhosh in Bengaluru; Editing by Alan Barona)