President-elect Joe Biden has selected David Kessler, a close adviser on the coronavirus crisis, to help lead the incoming administration’s efforts to accelerate the manufacturing, distribution and administration of coronavirus vaccines, the Biden transition team announced Friday morning.

His appointment comes at a pivotal moment — as the president-elect has begun spelling out plans to speed up the Trump administration’s sluggish effort on vaccinations to protect against covid-19, the disease caused by the deadly virus. Biden, in a speech Thursday night, said he would ask Congress for $20 billion — part of a larger economic and health package targeting the pandemic — to provide a more aggressive federal role in the vaccine rollout.

Those steps include adding many more vaccination sites and expanding the public health workforce to administer vaccines and do outreach to encourage Americans to get the shots.

According to a transition official, speaking on the condition of anonymity about details not publicly announced, Kessler will essentially take over the role played by Moncef Slaoui, who has been the chief scientific adviser to Operation Warp Speed, the Trump administration’s public-private initiative to hasten the manufacture and distribution of vaccines to curb the pandemic.

The transition official said that Operation Warp Speed was created by the outgoing administration to develop a vaccine to protect people from the coronavirus, while the Biden administration’s central focus will be on getting Americans immunized. The official said, “Warp Speed is the Trump administration’s name. We are going to phase in a new structure that will have its own name,” adding that many of Warp Speed’s employees will remain working in the revised structure.

Beginning last March during the presidential campaign, Kessler, a pediatrician and lawyer, briefed Biden on the pandemic several times a week. People close to the Biden transition effort say that Biden grew to trust Kessler’s judgment and likes him personally.

The transition official said Kessler will be an adviser, not running the vaccine effort, and will be based at the Department of Health and Human Services under secretary-designate Xavier Becerra. The news about Kessler and his new role was reported first by the New York Times.

Within the Food and Drug Administration and outside groups that work closely with the agency, Kessler provokes strong reactions. He gets praise for his extensive work on public health, especially on tobacco and nutrition issues, and criticism for his penchant for stirring controversy.

Kessler was head of the FDA from 1990 to 1997, under presidents George H.W. Bush and Bill Clinton, and worked to accelerate the first AIDS drugs. He tried to regulate cigarettes as “drug-delivery devices” — an effort that ended in a stinging court defeat for the agency. A 2009 law finally gave the FDA the authority to regulate cigarettes.

He has served as an expert witness in lawsuits against the drug industry. For example, several years ago, he wrote a report saying Johnson & Johnson and its Janssen subsidiary broke the law in marketing its antipsychotic drug Risperdal for use in children and adolescents. Johnson & Johnson is now working closely with Operation Warp Speed, the government vaccine effort that Kessler will advise. Kessler has also served as an expert witness in litigation involving opioids.

Kessler is one of eight people the transition announced early Friday who will work on the government’s coronavirus response in various capacities.

Among them, Andy Slavitt will become a senior adviser to Jeff Zients, the Biden White House’s coronavirus response coordinator. Slavitt was an acting administrator under President Barack Obama of the Centers for Medicare and Medicaid Services. Since then, he has formed a health think tank and advocacy organization and has been an outspoken critic of Trump-era health policies, especially regarding the Affordable Care Act.

Some of the incoming advisers are Obama alumni who also are veterans of a group called Protect Our Care, which was founded to try to prevent repeal of the ACA. They include Vidur Sharma, who is becoming a policy adviser for coronavirus testing on the Biden White House’s Domestic Policy Council, and Ben Wakana, who will have a communications role.

Kessler had been talked about as a potential head of the FDA in recent months. Now, the names mentioned most frequently are Janet Woodcock, a top agency career official who is said to be in line for the job of acting commissioner when the Biden administration takes over, and Joshua Sharfstein, a former deputy commissioner who is vice dean for public health practice and community engagement at the Johns Hopkins Bloomberg School of Public Health.

Under Kessler, the FDA implemented a requirement that food manufacturers adopt standardized nutrition labels. In a move that attracted widespread publicity, the FDA seized 2,000 cases of Citrus Hill Fresh Choice orange juice, arguing it was misleading to call it “fresh” because it was made from concentrate. The FDA under Kessler also instituted a moratorium on silicone-breast implants that was lifted in 2006.

After leaving the FDA, Kessler, 69, served as dean of the Yale School of Medicine and then dean of the medical school at the University of California at San Francisco, where he is still on the faculty.

A decade ago, Kessler wrote the “The End of Overeating,” a book arguing that the sugar, fat and salt content in food stimulates people’s appetites, leading to excessive weight gain and health problems such as diabetes, obesity and heart disease. More recently, he wrote “Fast Carbs, Slow Carbs,” which said that certain processed starches, specifically those with wheat and corn, cause people to overeat and gain weight.