Dr. Stephen M. Hahn, who became commissioner of the Food and Drug Administration just weeks before the coronavirus pandemic began, resigned on Wednesday as the administration of President Biden began.
Dr. Janet Woodcock, the longtime head of the F.D.A.’s Center for Drug Evaluation and Review, will serve as acting commissioner, according to an agency official.
Beginning in May, Dr. Woodcock had been assigned to Operation Warp Speed, the former administration’s program to accelerate vaccine and treatment development against the coronavirus.
She has worked at the F.D.A. since 1986, serving in a variety of key roles, among them chief medical officer and deputy commissioner.
The Biden administration has not yet nominated a permanent commissioner, but Dr. Woodcock is one of the candidates under consideration, according to several advisers to the new president’s transition team. Dr. Amy Abernethy, principal deputy commissioner, is also under consideration, as is Dr. Joshua Sharfstein, a former agency official, who is vice dean for public health practice and community engagement at Johns Hopkins University.
Dr. Hahn’s resignation was expected, part of the routine departure of senior political appointees that happens when a new administration takes office. In a farewell message to the F.D.A. staff on Wednesday, he wrote: “As a nation, and as a public health agency, we faced some big challenges and turbulent times over the past year, most notably those stemming from the Covid-19 pandemic. Through it all, F.D.A. employees have been critical in helping to respond to the disease with very real scientific advances like the authorization of the first nonprescription OTC [over the counter] Covid test, the authorization and approval of an anti-viral agent and the first two F.D.A. authorized Covid-19 vaccines.”
Dr. Hahn faced considerable criticism over the course of the pandemic, accused of bowing to political pressure from President Trump and the White House in granting emergency use authorizations for unproven treatments like hydroxychloroquine that did not produce evidence that they worked. In recent months, he has presided over reviews of the first vaccines to be allowed against the virus, the Pfizer and Moderna products.
In the past under other presidential administrations, Dr. Woodcock, 72, has been in the running for the F.D.A.’s top post. She was first brought to the F.D.A.’s drug division by Dr. David Kessler, the former F.D.A. commissioner who was named the chief science officer for the Biden administration’s vaccine efforts, which will no longer be called Operation Warp Speed.
The Biden administration has not indicated when an F.D.A. commissioner would be named.