Dr. Francis S. Collins, the National Institutes of Health director who has led the agency for more than a decade and through three presidential administrations, said on Tuesday that he would step down from his post by the end of the year.
President Biden is expected to nominate a replacement, who will have to be confirmed in an evenly divided Senate, to manage a budget of over $40 billion.
“No single person should serve in the position too long,” Dr. Collins said in a statement. “It’s time to bring in a new scientist to lead the N.I.H. into the future.”
Dr. Collins, 71, was appointed in 2009 by President Barack Obama after more than a decade leading the National Human Genome Research Institute, which is part of the N.I.H.
Mr. Biden on Tuesday lavished praise on Dr. Collins, whom he called “one of the most important scientists of our time.”
“After I was elected president, Dr. Collins was one of the first people I asked to stay in his role with the nation facing one of the worst public health crises in our history,” Mr. Biden said. “Millions of people will never know Dr. Collins saved their lives. Countless researchers will aspire to follow in his footsteps. And I will miss the counsel, expertise and good humor of a brilliant mind and dear friend.”
On Tuesday, the N.I.H. said that Dr. Collins would return to his laboratory there, which is studying the causes of and prevention for Type 2 diabetes and new therapies for Hutchinson-Gilford Progeria Syndrome, a form of premature aging.
A geneticist by training, Dr. Collins oversees 18,000 employees and a sprawling federal research program, spread across 27 institutes and centers in 75 buildings over 300 acres of land in Bethesda, Md.
During the pandemic, Dr. Collins helped found a project known as ACTIV, which enabled trials on antivirals and other treatments for Covid-19 to run at many sites at once. He has also been a regular spokesman for vaccines for both the Trump and Biden administrations.
He endorsed Mr. Biden’s decision this summer to require federal workers to be vaccinated against the coronavirus, and has said that businesses asking employees for proof of vaccination or regular testing were taking steps “in the right direction.”
An outspoken Christian who has written widely on the mingling of religion and science, Dr. Collins has been deployed by the Biden administration as a surrogate among vaccine-hesitant conservatives, speaking on Christian radio and addressing evangelical groups to make the case for getting inoculated.
He has often criticized what he views as the politicization of the pandemic. “Imagine you were an alien who landed on planet Earth,” he said in one appearance on CNN last year when asked to comment on a political rally for President Donald J. Trump at which few attendees wore masks. “You would scratch your head and think, ‘This is just not a planet that has much promise for the future.’”
Dr. Collins is known in the medical community as a folksy, colorful personality. He rides a motorcycle, and last year recorded a Covid-19-themed cover of “Puff the Magic Dragon” on a guitar ornamented with a double helix.