Republican senators are growing increasingly uncomfortable over President Trump’s unconventional forays into health policy, specifically the president’s support for Health and Human Services Secretary Robert F. Kennedy Jr. and his attempts to rewrite the children’s vaccination schedule despite strong skepticism from the medical community.
One lawmaker said Republicans are “starting to break ranks” over it.
Trump gave Kennedy a big boost Monday by warning mothers not to give their newborns multiple vaccines at once and advising against Tylenol use during pregnancy.
Trump identified acetaminophen, the common over-the-counter medication, as a likely cause of autism — despite scant research showing a clear link — and warned pregnant women: “I want to say it like it is: Don’t take Tylenol. Don’t take it. Fight like hell not to take it.”
That controversial claim was immediately challenged by Sen. Bill Cassidy (La.), the Republican chair of the Senate Health, Education, Labor and Pensions Committee and a medical doctor.
“HHS should release the new data that it has to support this claim. The preponderance of evidence shows that this is not the case. The concern is that women will be left with no options to manage pain in pregnancy,” Cassidy wrote on social media.
In comments reminiscent of the off-the-cuff advice the president shared in 2020 about unorthodox COVID-19 treatments, Trump — with Kennedy at his side — on Monday also shared his “feeling” that that children’s vaccination protocols should be overhauled.
Cassidy told The Hill in an interview that he is concerned about former Centers for Disease Control and Prevention (CDC) Director Susan Monarez’s testimony to his committee that Kennedy pressured her to approve changes to childhood vaccine recommendations regardless of the scientific data.
“You’re going to change a medical guideline without science?” Cassidy asked in disbelief about the prospect of changing medical guidelines without a clear scientific basis.
“I mean, you’re going to build a bridge without physics? You’re going to fly a plane without engineering? All these things that we very much depend upon, our lives depend upon, you require people who have kind of have made it their life’s work to build a good plane, a good bridge,” he said.
“In my mind, you want people whose life’s work has been to make sure that he have safe and effective vaccines that are indicated for the things for which they are being recommended,” he said.
Cassidy, a former practicing gastroenterologist and liver specialist, expressed his alarm at last week’s hearing over reports that the CDC’s Advisory Committee on Immunization Practices (ACIP), which Kennedy overhauled by firing all 17 of its previous board members and replacing them with people perceived to be more loyal to his anti-vaccine agenda, planned to change its recommendation for giving the hepatitis B vaccine to newborns.
“If someone is infected [with hepatitis B] at birth, they have a 95 percent chance of becoming chronic. Now, I read something about how they’re going to change [the recommended vaccination target] to one month [after birth],” Cassidy told The Hill. “That misses the point. If you’ve been infected at birth, getting the vaccine dose one month after will not prevent that infection. It’s one month after, and the person has already become chronically infected.”
Facing strong pushback from Cassidy and other critics last week, the ACIP decided to postpone a vote on a proposal to recommend delaying the first dose of hepatitis B vaccine until an infant is at least 1 month old.
The committee advised Thursday that the MMRV vaccine should not be given to children younger than 4 years old and recommended children in that age group should instead receive two separate vaccines: one for measles, mumps and rubella (MMR), and one for varicella, also known as chickenpox.
Sen. Susan Collins (R-Maine), a senior member of the Senate Health Committee who faces a competitive reelection race in 2026, said she found Monarez’s testimony that Kennedy is subverting the administration’s health policy recommendations to serve a political agenda and pushing aside science “disturbing.”
“It appears that she was under a lot of pressure to approve recommendations that may come from the [vaccine advisory] committee that may lack scientific basis, so that is disturbing and would undermine our public health efforts,” Collins told The Hill.
“I’m very pleased that Chairman Cassidy is having these hearings,” she added.
Sen. Lisa Murkowski (R-Alaska), another senior member of the Health Committee, said she was alarmed by Monarez’s testimony to the Senate about the inner workings of Kennedy’s health policy recommendations.
“There were a lot of things that I heard … that I found very unsettling and very concerning,” she said.
GOP lawmakers say privately that Kennedy has become a political liability for Trump and the broader Republican Party, but they note he is secure in his job as long as Trump feels he’s politically useful.
“When it involves children, it creates a lot of angst among people, among families,” said a Republican senator who requested anonymity to comment on the political dangers posed by Kennedy pressing forward with his unorthodox health policy views.
The lawmaker, however, observed that Trump thinks Kennedy has brought new voters into the MAGA coalition.
“I think the president sees the people who support the efforts of Secretary Kennedy as new Republican voters, and he likes that. He wants to build a bigger tent, and I think that’s been his thought on [Kennedy] for a long time,” the senator said.
A second Republican senator who requested anonymity said Kennedy is losing support among Republicans on Capitol Hill who worry that if the administration makes sudden changes to vaccine recommendations for children or changes federal policies in a way that results in vaccines becoming significantly more expensive, it could trigger a political backlash or, even worse, a future epidemic.
“You see a lot of Republicans starting to break ranks here, and there’s a lot of noise. I think it will come down to Trump and what his tolerance level is for all this noise around [Kennedy],” the senator said.
The lawmaker said Trump doesn’t like bad headlines and negative media coverage, something that has dogged Kennedy since his Senate confirmation proceedings.
“I don’t think he likes all the noise. He hasn’t liked that previously. He has a really low tolerance level for that, but Bobby Kennedy is different. He’s not like anyone else in the Cabinet,” the senator added.
Kennedy, the son of former Attorney General and Sen. Robert F. Kennedy (D-N.Y.) and the nephew of former President John F. Kennedy, has old-school star power that no one else in Trump’s Cabinet can match.
As a longtime Democrat who threw his support to Trump in the 2024 election, Kennedy’s allegiance helps support Trump’s frequent claims that today’s Democratic Party has gone off the rails and bears little resemblance to what it was in the days of JFK and Camelot.
Some of Kennedy’s relatives, including his sister Kerry and his nephew, former Rep. Joseph P. Kennedy III (D-Mass.), have criticized his health policy views and called on him to resign.
