Martin Makary, President Donald Trump's nominee to run the U.S. FDA, will be tasked with maintaining the agency's gold standard status among international drug regulators while contending with cost cuts, and answering to a vaccine skeptic for a boss in Health Secretary Robert F. Kennedy Jr.

He is set to take over an agency already embroiled in controversy after the mass firing of federal employees and the cancellation of a meeting of Food and Drug Administration advisers meant to discuss the seasonal flu vaccine shortly after Kennedy was confirmed.

Makary will appear in front of the Senate Health, Education, Labor and Pensions Committee for his confirmation hearing on Thursday. He will likely face questions from Democrats on mifepristone - a drug used for medical abortion that has faced efforts to make it unavailable or illegal in Republican-controlled states - and his position on vaccines.

Makary, a physician at Johns Hopkins Hospital in Baltimore, has spoken out against over treatment in the U.S., calling it "an epidemic of inappropriate care."

He also raised concerns about a number of public health efforts during the COVID-19 pandemic, touting the protection received from natural immunity and opposing vaccine mandates for the general public — stances that put him at odds with many public health experts.

Makary will be working for Kennedy, who has expressed goals of ending chronic disease as well as breaking ties between FDA employees and the pharmaceutical industry.

Kennedy has sown doubts in the past about the safety and efficacy of vaccines that have helped curb disease and prevent deaths for decades, but disputes the anti-vaccine label.

Although Makary has staked out contrarian positions on other topics in the past, those familiar with his work say he believes in the benefit of vaccination.

"He's a very bright guy, and he's accomplished a lot in the medical world," said Dr. Cody Meissner, chief of pediatric infectious diseases at Tufts Children's Hospital, who has corresponded with Makary and co-wrote an editorial with him against masks for children during the COVID pandemic.

"He understands the importance of vaccines, and I would in no way consider him to be an anti-vaxxer," Meissner said.

Democratic U.S. Senators Patty Murray, Tammy Baldwin and Angela Alsobrooks wrote a letter to Makary last week about the cancellation of a meeting of the independent panel that advises the FDA on vaccine policy. The committee had been set this month to discuss the composition of the influenza virus vaccines for the 2025-2026 flu season.

"We expect you to answer questions about whether you will adopt a position of responsible public health leadership or continue the Trump administration’s current, troubling trajectory into vaccine skepticism," they wrote.

Makary may also face pressure to further reduce head count at the FDA after hundreds of jobs were already cut last month as part of the effort to slash the size of the federal government by Elon Musk and his Department of Government Efficiency. Many of those cuts were quickly rescinded and the agency is now offering early retirement.

Industry veteran Jeremy Levin, chief executive of biotechnology company Ovid Therapeutics, said Makary may have to stand up for the agency in the face of those DOGE efforts.

"A lot of people who are looking to simply cut costs have raised the specter - but not the fact - that they will do wholesale cutting at the FDA. In the event that they propose that," Levin said, "I'm hopeful that Marty will be in a position to push back."