“Efforts to undermine public confidence in proven cures are not just uninformed — they’re dangerous,” McConnell said in a statement Friday. “Anyone seeking the Senate’s consent to serve in the incoming Administration would do well to steer clear of even the appearance of association with such efforts.”

The 82-year-old lawmaker’s statement appeared to be directed at Trump’s pick for health secretary, Robert F. Kennedy Jr., after a report that one of his advisers filed a petition to revoke approval for the polio vaccine in 2022. That vaccine is widely considered to have halted the disease in most parts of the world.

McConnell’s words were a sign that Kennedy, who has long advanced the debunked idea that vaccines cause autism, could face some resistance in the soon-to-be GOP-controlled Senate.

“Mr. Kennedy believes the Polio Vaccine should be available to the public and thoroughly and properly studied,” said Katie Miller, the transition spokeswoman for Kennedy, in response to questions.

The New York Times reported that the petition was filed by a lawyer now helping Kennedy select candidates for federal health positions in the incoming administration.

Any individual or company can file a petition with the Food and Drug Administration, which typically fields hundreds of requests at any time relating to various food, drug and medical issues. Most petitions are denied, but the FDA is required to respond to each one in writing.

Vaccines have been proven to be safe and effective in laboratory testing and in real-world use in hundreds of millions of people over decades — they are considered among the most effective public health measures in history.

McConnell contracted polio at 2 years old but survived because of “the miraculous combination of modern medicine and a mother’s love,” according to the statement. He praised the “saving power” of the polio vaccine for the “millions who came after me.”

Senate Majority Leader Chuck Schumer, D-N.Y., said in a post on X that it was “outrageous and dangerous for people in the Trump Transition to try and get rid of the polio vaccine that has virtually eradicated polio in America and saved millions of lives.

He said Kennedy should clarify his own position on it.

Trump announced last month his selection of Kennedy, saying Kennedy would work to protect Americans “from harmful chemicals, pollutants, pesticides, pharmaceutical products, and food additives.”

But that pick was met with alarm from scientists and public health officials, who fear Kennedy would unwind lifesaving public health initiatives such as vaccines.

Kennedy has pushed other conspiracy theories regarding vaccines, such as that COVID-19 could have been “ethnically targeted” to spare Ashkenazi Jews and Chinese people, comments he later said were taken out of context. He has repeatedly brought up the Holocaust when discussing vaccines and public health mandates.

Kennedy said he plans to remake the Department of Health and Human Services, an agency with sprawling reach and a $1.3 trillion budget, if he is approved. He has suggested the FDA is beholden to “big pharma,” and his anti-vaccine nonprofit has called on it to stop using COVID-19 vaccines.

During the COVID-19 epidemic, his nonprofit group, Children’s Health Defense, petitioned the FDA to halt the use of all COVID vaccines. The group has alleged that the FDA is beholden to “big pharma” because it receives much of its budget from industry fees and some employees who have departed the agency have gone on to work for drugmakers.

Children’s Health Defense currently has a lawsuit pending against a number of news organizations, among them The Associated Press, accusing them of violating antitrust laws by taking action to identify misinformation, including about COVID-19 and COVID-19 vaccines. Kennedy took leave from the group when he announced his run for president but is listed as one of its attorneys in the lawsuit.