Dr. Heidi Overton, President Trump’s nominee to lead the US Food and Drug Administration, appeared to break with her boss on Thursday, strongly stating that the MMR vaccine was “not lethal” as Trump has claimed and that it is safe, effective and “our best tool right now in the public health response to the measles outbreak.”

Overton was questioned by the Senate’s Health, Education, Labor and Pensions committee, whose members will vote on whether to advance her nomination to the full Senate.

HELP Committee Chairman Bill Cassidy, a Republican and doctor from Louisiana, and others pressed her on her recent involvement in Trump’s executive order on vaccines, which aims to scale back the number of vaccinations routinely recommended for children. It also prioritizes splitting up the measles, mumps and rubella, or MMR, vaccine into individual components and says they should be given at separate medical visits — an approach that experts say would decrease uptake of the vaccine and worsen the nation’s growing number of measles cases, which are at their highest level since the disease was declared eliminated in the US decades ago.

“Are there any vaccines on the US market right now which are unsafe?” Cassidy asked.

“Every vaccine on the US market right now are safe and effective, according to the FDA,” Overton said.

Cassidy then asked what she would do if Trump asked her to do something that goes against science.

“I would give him my best advice, and I would follow the statutory requirements for the role of FDA commissioners regarding individual product determinations for safety and efficacy, and that would be what would guide every decision if confirmed to this role,” Overton said.

Path to nomination

Overton has been a powerful but largely behind-the-scenes presence in the second Trump administration, serving as deputy assistant for domestic policy, where she oversaw health initiatives for the White House.

The last FDA commissioner, Dr. Marty Makary, resigned in May amid intense pressure. Kyle Diamantas, the acting commissioner who had been the agency’s deputy commissioner for food, repeatedly turned down the position, even when asked directly by Trump, a senior administration official with knowledge of the process previously told CNN.

Overton, a physician, graduated from the University of New Mexico School of Medicine and was a surgical resident at Johns Hopkins University, according to her LinkedIn profile. She’s board-certified in public health and general preventive medicine, according to the American Board of Medical Specialties. At age 37, she would be one of the youngest people ever to lead the FDA.

Overton joined Trump’s first administration as a White House fellow on the Domestic Policy Council during the Covid-19 pandemic. She later finished her Ph.D. in clinical investigation at Johns Hopkins Bloomberg School of Public Health. She was chief policy officer at the America First Policy Institute, a pro-Trump think tank; other institute staff who have been hired into high-level posts in the second Trump administration include Agriculture Secretary Brooke Rollins and former Attorney General Pam Bondi.

Overton also has experience as a patient. She said in her opening statement that she lives with type 1 diabetes, an autoimmune condition in which the body attacks its own insulin-producing cells in the pancreas. Overton revealed she was diagnosed with type 1 diabetes as an adult.

A number of promising cell therapies are in development to treat and potentially even reverse the condition, but progress in the field has been hampered in recent years by a backlog of cell and gene therapies at the FDA. As head of the agency, Overton would be in a position to streamline the process for biotech companies working on new therapies.

As commissioner, Overton would be in charge of a behemoth of an agency. The FDA has about 16,000 staffers and a roughly $7 billion annual budget. The FDA has been hit hard by the Trump administration’s reduction-in-force cuts, some 4,600 workers since 2024, according to Office of Personnel Management data.

Despite her close ties to the White House, she isn’t a shoo-in for the role. Cassidy has said he was concerned about her limited experience.

“While I respect Dr. Overton’s experience as a physician, I have strong concerns about her nomination to be FDA Commissioner. Her lack of managerial experience does not prepare her well for leading a large organization that is already dealing with staffing and morale issues,” Cassidy posted on social media ahead of the hearing.

Others went even further.

Dr. Peter Lurie, a former FDA official who is now president of the nonprofit Center for Science in the Public Interest, said the agency has shed thousands of employees, including food safety inspectors “and is struggling to keep up with food recalls and outbreaks of foodborne illness.”

“Despite efforts to frantically re-staff, this is an agency in crisis. This is no time for a commissioner who needs on-the-job training,” Lurie said in a statement.

Although some may be skeptical of her qualifications, Overton clearly has the president’s support.

“Dr. Heidi has been a ROCKSTAR in my Administration, where she has worked directly with Secretary Kennedy, Dr. Oz, and team, to deliver on the MOST TRANSFORMATIVE Health Agenda in History. She is known to take on the HARDEST issues, and bring me solutions that work best for the Country… She is SMART and RESPECTED by all!” Trump said in a Truth Social post announcing her nomination last month.

Overton on the issues

Thursday’s hearing was one of the first opportunities for Americans to hear directly from Overton, and she faced tough questions on her support for vaccines as well as access to medication abortion, agency reform and whether she intends to roll back tobacco regulation.

As FDA commissioner, Overton would be in charge of the nation’s drug policy, including the agency’s approval of mifepristone, one of two medications taken to induce abortions, which is currently the subject of ongoing litigation.

One of the stated goals of Project 2025, a document created by the conservative Heritage Foundation that has become the basis of many of the Trump administration’s policies during his second term, is to restrict access to mifepristone or to revoke FDA approval for the drug altogether.

While at the American First Policy Institute, Overton cheered the US Supreme Court’s June 2022 decision to overturn Roe v. Wade, calling it a “huge victory for life.” She’s also the author of policy brief that called medication abortions “dangerous to women,” despite decades of evidence showing that abortion medications are safe and effective, according to the American College of Obstetricians and Gynecologists.

These views have already alienated some members of the HELP Committee.

“Heidi Overton is a far-right, anti-abortion extremist who has no business leading the FDA,” Sen. Patty Murray, a Democrat from Washington, said on social media. “I will vote no.”

When asked by several senators Thursday about her position on allowing more flavored vapes on the market, Overton said that she agreed it was important to protect kids from “illegal substances, and vapes and flavored vapes” but that career scientists at the FDA had recommended the authorizations of new flavored vaping products because “so many adults are using flavors” to quit smoking.

In contrast to her direct answers on vaccines, she largely dodged questions about her stance on the abortion drug mifepristone.

When asked by Sen. Tammy Baldwin, a Democrat from Wisconsin, whether she thought the FDA should change the label or conditions of approval for mifepristone, Overton noted that the agency is conducting an internal review of the drug’s safety.

“I can’t prejudge the determination of a safety review that is currently ongoing,” Overton said, adding that if she is confirmed, she expects mifepristone would be one issue that’s “immediately on my desk.”

Baldwin did not seem satisfied by her answer.

“I haven’t been encouraged by what I’ve seen, but I urge you to indeed follow the well-established science on safety and efficacy of mifepristone,” Baldwin replied.

Cassidy pointed out that the FDA once required in-person visits and ultrasounds before doctors could prescribe abortion pills. Sen. Lisa Murkowski, a Republican from Alaska, said she was concerned that in her state, where access to care is challenging, requiring in-person visits would restrict women’s ability to take the drug “if, in fact, the move to require in-person dispensing of the medication as opposed to telehealth appointments is the direction,” she said.

Asked several times whether she would ever disagree with Trump or tell him he wrong, Overton declined to directly answer.

“It is the president who sets the policy directions, but he works with all of his advisers to get the best information. My experience has been, he wants to make the best decision and the best information,” she said.

Sen. Maggie Hassan, a Democrat from New Hampshire, said she was disappointed to hear that.

“The American people need a leader at the FDA who is able to say that the president is wrong when he is,” Hassan said.