Robert F. Kennedy Jr. is best known as a vaccine skeptic but the Trump team has curbed his most polarizing views ahead of his high-stakes Senate confirmation hearing to lead the Department of Health and Human Services.

Mr. Kennedy recently resigned as chairman of the board of Children’s Health Defense, a prominent anti-vaccine group, and ethics filings show he will no longer collect fees for his work on vaccine lawsuits that involve the U.S. government.

Also, there are signs that Mr. Kennedy’s ardent anti-vaccine allies are being sidelined in favor of more traditional staff at HHS.

Veteran lawyer Heather Flick, who served at HHS during Mr. Trump’s first term, is slated to serve as chief of staff while Kennedy allies such as vaccine injury lawyer Aaron Siri are unlikely to join the department.

“I am seeing traditional conservatives manning senior positions at HHS, with the transition team resisting any outright vaccine skeptics. They want conservative guardrails around Kennedy, making sure he drives the president’s agenda and does not get sidetracked into a rabbit hole of anti-science and anti-vaccine,” said Lawrence O. Gostin, a global health law professor at Georgetown University.

Efforts to tamp down the more polarizing aspects of his “Make American Healthy Again” agenda coincide with growing alarm about a decline in the use of childhood vaccines that have eradicated, or nearly erased, serious diseases such as polio and measles.

Any return of those scourges would create blowback on President Trump, who pledged to let Mr. Kennedy “go wild on health.” That’s left the pharmaceutical industry, whose Wall Street shares tanked upon Mr. Kennedy’s nomination in November, cautiously optimistic or in wait-and-see mode about what he tells Congress.

“In the case of Kennedy, he has to speak for himself,” said Peter Pitts, a former associate commissioner at the Food and Drug Administration and president of the Center for Medicine in the Public Interest, which is pro-vaccine.

He pointed to a December episode in which Mr. Kennedy assured senators that he was “all for” the polio vaccine after one of his attorney associates cast doubt on the shot.

“It’s unfair to judge a potential cabinet pick by what other people are saying. Listen to what the guy says,” Mr. Pitts said.

Mr. Kennedy is scheduled for a confirmation hearing Wednesday before the Senate Finance Committee, which will vote on whether to advance his nomination to lead HHS, a sprawling agency with a $1.7 trillion budget.

The Senate Committee on Health, Education, Labor and Pensions will hold a courtesy hearing on Thursday to further explore Mr. Kennedy’s views and qualifications.

He’s faced pressure from the political right, including former Vice President Mike Pence, who questioned Mr. Kennedy’s commitment to the pro-life movement.

Yet his anti-vaccine comments, particularly about a possible link between vaccines and autism, are the most prominent sticking point for senators.

Efforts to rein in Mr. Kennedy reflect the schism between Mr. Kennedy’s longstanding vaccine views and his broader, more popular efforts to get Americans to live healthier lifestyles, eat nutritious foods and get to the root cause of diseases and autism.

A few Democrats are open to Mr. Kennedy’s nomination as it pertains to fighting corporate influence and improving nutrition. Yet many Democrats are opposed to the nominee. They claim his actions in 2019 fueled a measles outbreak in Samoa. Without Democrats’ support, Mr. Kennedy could only afford to lose three Republican confirmation votes.

The situation has left the pharmaceutical industry in a tenuous posture.

“If Kennedy begins to cast doubt on important vaccines and medicines, industry leaders will show disapproval. But for now, they do not want to alienate the president,” Mr. Gostin said.

The Pharmaceutical Research and Manufacturers of America — a major lobbying group — referred Monday to a November statement that says the Trump administration should rethink a Biden-era drug price-negotiation program and support efforts to fight disease and eliminate diseases like polio and smallpox.

“We want to work with the Trump administration to further strengthen our innovation ecosystem and improve health care for patients,” PhRMA said.

A person in the immunization field told The Washington Times that vaccinators are also “hopeful” about the path ahead but remain uneasy about Mr. Kennedy’s positions.

“Of course, we hope for the best. We know that most Americans strongly support vaccines. But I don’t think any of us are optimistic. We’ve seen the damage that RFK can do, and we don’t know what to expect from Trump,” said the person, who requested anonymity given the ongoing political process.

Mr. Kennedy has been trying to reassure leery senators for weeks. He says he won’t take away anyone’s vaccines but wants more data to ensure the shots are safe.

“I think that’s perfectly fair, because if his platform is ’trust through transparency,’ he’s got my vote,” Mr. Pitts said.

Mr. Kennedy’s recent support for the polio vaccine was aimed at senators like Mitch McConnell, the Kentucky Republican who suffered from the disease as a child, and Americans who are concerned that dropping vaccination rates will allow polio, measles and other diseases to make an ugly return.

National coverage with state-required vaccines among kindergartners dropped from 95% to about 93% from the school year ending in 2020 to 2022, ranging from 92.7% for diphtheria, tetanus, and acellular pertussis vaccine — the DTaP vaccine — to 93.1% for polio, according to the Centers for Disease Control and Prevention.

All states require proof of certain vaccinations to attend public school, though many places offer exemptions for religious reasons or personal beliefs.

During the 2022-2023 school year, the exemption rate rose by 0.4 percentage points to 3.0%, the CDC said. Exemptions increased in 41 states and exceeded 5% in 10 states.

Some groups are hoping Mr. Kennedy sticks to his underlying focus on autism without pushing a harmful claim about vaccines.

“RFK is right to see an autism crisis — one we urgently need to address,” said Jill Escher, president of the National Council on Severe Autism. “But the last thing we need is to see a reduction in childhood vaccination and its intolerable risk to children’s health.”

Jayasree K. Iyer, CEO of the Access to Medicine Foundation, a group that prods the pharmaceutical industry to help people in low- and middle-income countries, said vaccines save lives and “are critical in the fight against new and existing health threats.”

“We cannot speak for individual companies or the industry’s position, but from our independent view of the industry, the industry remains cautiously hopeful,” she said about the U.S. path under Mr. Kennedy. “It is important to recognize the need for vaccines and coverage of vaccinations to ensure populations globally and in the United States are safe.”

• Tom Howell Jr. can be reached at thowell@washingtontimes.com.