The US Department of Health and Human Services is terminating a contract with drugmaker Moderna to develop a vaccine to protect against bird flu amid the agency’s broader efforts to reevaluate therapies that use mRNA technology.

HHS has notified Moderna that it is canceling a nearly $600 million contract for vaccines for flu strains that could trigger future pandemics.

The Department of Health and Human Services (HHS) is canceling hundreds of millions of dollars in funding pledged to Moderna to help the company develop, test and license mRNA-based vaccines to combat pandemic flu viruses,