"It's hard to argue that that's not going to have some impact on the continuity and also make businesses, companies that need to collaborate with BARDA, a little bit more reluctant now to embrace BARDA now that there's a cloud hanging over it and some uncertainty about the leadership," he said.

Gottlieb, who led FDA for two years during the Trump administration, called Bright "very effective" in the job and said they worked together on an Ebola vaccine and on smallpox treatments.

"He was a vaccine expert, so I was sorry to see him go," Gottlieb said.

Bright was transferred last week to a new role at the National Institutes of Health. He has argued he was pushed out of his role over his resistance to investing in the anti-malaria drug hydroxychloroquine, which President Donald Trump had treated as a treatment for coronavirus without scientific evidence. Bright's lawyers said he plans to file a whistleblower complaint with the HHS inspector general.

"I don't think doctors should be using it outside of protocols at this point, given the fact that we've had now accruing evidence demonstrating really no benefit and some indication that it could be causing harm," Gottlieb said of hydroxychloroquine. "I think it's still reasonable to conduct clinical studies with it to see if it could be effective as a treatment. But we've done a lot of clinical studies to date and ... we haven't turned over a card that's really shown that the drug's effective."