Donald Trump announced on Thursday he will nominate the former independent presidential candidate Robert F Kennedy Jr as the US secretary of health and human services (HHS) in his administration.

Kennedy, an anti-vaccine activist, will be a contentious pick to lead the US health department, and the role will need to be confirmed by the Senate.

“Donald Trump’s selection of a notorious anti-vaxxer to lead HHS could not be more dangerous – this is cause for deep concern for every American,” said Senator Patty Murray, a Democrat of Washington state, adding the move could “set America back in terms of public health, reproductive rights, research, and more”.

Trump, in a post on his Truth Social platform on Thursday, claimed Americans had “for too long” been “crushed by the industrial food complex and drug companies who have engaged in deception, misinformation, and disinformation when it comes to Public Health”.

“HHS will play a big role in helping ensure that everybody will be protected from harmful chemicals, pollutants, pesticides, pharmaceutical products, and food additives that have contributed to the overwhelming Health Crisis in this Country,” the president-elect wrote.

“Mr. Kennedy will restore these Agencies to the traditions of Gold Standard Scientific Research, and beacons of Transparency, to end the Chronic Disease epidemic, and to Make America Great and Healthy Again!”

Trained as an environmental lawyer, Kennedy, 70, is the son of the former attorney general and presidential candidate Robert F Kennedy and the nephew of president John F Kennedy.

Kennedy had attempted to win the White House himself during the 2024 presidential election but his bid never took off in the polls. After ending his attempt, he eventually endorsed Trump, who promised to put him into an influential position with regard to health policy.

“He’s going to help make America healthy again,” Trump said of Kennedy, in remarks after winning the election. “He’s a great guy and he really means it. He wants to do some things, and we’re going to let him go to it.”

However, shortly after the presidential election, Trump’s transition co-chair Howard Lutnick told CNN that Kennedy was “not getting a job for HHS”.

Kennedy became one of Trump’s top surrogates during the campaign, which came as a surprise to some observers as he is the scion of a famous Democratic dynasty and has had a long history of environmental activism often in causes to which Trump will probably do great damage.

Kennedy has also become well-known for his anti-vaccine beliefs and embrace of other conspiracy theories around health and wellness issues.

Trump has previously said he will let Kennedy “go wild on food” and “go wild on medicines” if re-elected, as well as wanting him to take care of women’s health. There has also been speculation he may be given influence over children’s health, too, which would particularly alarm proponents of vaccines. Kennedy has repeatedly claimed that childhood vaccines cause autism, a theory scientists have debunked.

Earlier this month, Kennedy declared on X that Trump would push to remove fluoride from drinking water on his first day of office, claiming that it was “an industrial waste” linked to a variety of health conditions. Health groups insist fluoride is safe.

Since Trump’s election victory, Kennedy has sought to allay concerns that he would seek to halt vaccinations. “We’re not going to take vaccines away from anybody,” he told NPR in an interview.

Despite this, some staff members at the Food and Drug Administration were considering a quick exit should Kennedy be selected for a prominent health role, according to NBC News. Shares of the vaccine makers Moderna, Pfizer and Novavax tumbled after news of Trump’s decision was first reported, Bloomberg reported.

Kennedy’s independent presidential campaign was marked by at times bizarre scandals that ranged from the revelation that part of his brain had been eaten by a worm to admitting to staging a dead bear corpse in Central Park as the victim of a hit-and-run accident.

Kennedy’s nomination to Trump’s government is likely to boost already strong fears that he is keen on appointing extremists and loyalists to his administration rather than experts and technocrats. It follows on jobs for the hard-right Stephen Miller on the issue of immigration, Fox News star Pete Hegseth at the Department of Defense and scandal-plagued Maga loyalist Matt Gaetz as attorney general.

In a statement following Trump’s announcement, Bill Cassidy, the Republican Louisiana senator and incoming chair of the Senate’s health, education, labor and pensions committee, said: “RFK Jr has championed issues like healthy foods and the need for greater transparency in our public health infrastructure. I look forward to learning more about his other policy positions and how they will support a conservative, pro-American agenda.”

Hakeem Jeffries, the House minority leader, expressed skepticism that Kennedy was the right choice but said it was up to the Senate to confirm or reject him. “Is RFK Jr the best qualified person in the United States of America to lead us forward as we grapple with an enormous amount of health challenges in this country? The answer is clearly he is not,” he said in comments reported by Politico.