Donald Trump has picked vaccine sceptic and former independent presidential candidate Robert F Kennedy Jr as his health secretary, as the president-elect continues to build his new administration.

Kennedy, commonly known by his initials RFK Jr, has a history of spreading health information that scientists say is false.

If his nomination is ratified by the Senate, he will lead a huge agency overseeing everything from food safety to medical research and welfare programmes.

The executive director of the American Public Health Association (APHA) said the organisation will “absolutely oppose” Kennedy’s nomination.

Speaking to BBC Newsday on Friday, Georges C Benjamin fiercely denounced Kennedy’s qualifications for the role.

“He is not competent by training, management skills, temperament or trust to have this job. He’s just absolutely the wrong guy for it,” Benjamin said.

“He is really just a person without a health background who’s already caused great damage in health in the country.”

Benjamin pointed to Kennedy’s previous comments questioning the safety and efficacy of vaccines, and what might happen if there were another pandemic during his tenure.

Benjamin continued: “We’re going advocate as loudly and as often as we can to make sure that people know what a risk he is to the public and to the public’s health.”

Kennedy’s nomination came amid a flurry of announcements on Thursday evening, with Trump also declaring his intention to nominate North Dakota Governor Doug Burgum as his interior secretary.

Trump said he would formally announce the selection of Burgum – a former businessman who ran against the president-elect for the Republican presidential nomination – on Friday.

He had initially teased the move during a speech to supporters at Mar-a-Lago – his first since election night – saying he would be appointing Burgum to a “very big position”, before seemingly deciding to dispense with the suspense.

Other nominations announced on Thursday include:

• Former Georgia Congressman Doug Collins as secretary of veterans’ affairs.
• Todd Blanche, Trump’s defence lawyer in his “hush money” criminal trial, to serve as deputy attorney general.
• Dean John Sauer, who represented Trump in a US Supreme Court case earlier this year, as solicitor general. He will be charged with supervising and conducting government litigation in the Supreme Court.
• Jay Clayton, former chairperson of the US Securities and Exchange Commission, as US attorney for the Southern District of New York, one of the most influential federal trial courts.

Trump said in a statement he was “thrilled to announce” Kennedy’s nomination.

Speculation had grown that Trump planned to hand his former rival a key healthcare role.

He told supporters at his election night victory party that Kennedy wanted to “help make America healthy again”.

“For too long, Americans have been crushed by the industrial food complex and drug companies who have engaged in deception, misinformation, and disinformation when it comes to Public Health,” Trump said in his statement on Thursday.

“Mr Kennedy will restore these Agencies [Health and Human Services] 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!”

The nominee hails from one of the most famous families in Democratic politics as the son of US Attorney General Robert F Kennedy and nephew of President John F Kennedy, both of whom were assassinated in the 1960s.

Now aged 70, the environmental lawyer ran for president this year as an independent after initially launching a Democratic primary bid, but he eventually suspended his own campaign, endorsing Trump.

He is known for his criticism of childhood vaccines, claiming in an interview last year: “I do believe that autism comes from vaccines.”

According to the Centers for Disease Control and Prevention, America’s national public health agency which is one of the bodies the US health secretary oversees: “Many studies have looked at whether there is a relationship between vaccines and ASD [autism spectrum disorder]. To date, the studies continue to show that vaccines are not associated with ASD.”

Kennedy, who was addicted to heroin for 14 years in his youth, has also talked about wanting to help tackle America’s substance abuse crisis.

‘We’re now seeing an epidemic of addiction, alcoholism,” he told the Daily Mail last year. “But also just loneliness, despair, disassociation, alienation.”

During his campaign for the White House, tales of Kennedy’s personal life more often caught the news than any major policy proposals. His admission that he had suffered from a brain worm, and a separate story about his dumping of a dead bear in New York’s Central Park, dominated headlines for days.

Democrats have been quick to condemn the pick, with Senator Patty Murray calling the choice “catastrophic” and labelling Kennedy a “fringe conspiracy theorist”.

Republican Senator Susan Collins said she had found some of Kennedy’s “statements to be alarming” but said she would grant him a fair hearing during confirmation proceedings.

Trump has been selecting his top team since winning the US election last week. His party is projected to win the House of Representatives, meaning the Republicans will run the White House and all of Congress.

Marco Rubio has been nominated for secretary of state and former Democrat Tulsi Gabbard for director of national intelligence. But his decision to nominate controversial Florida Congressman Matt Gaetz has raised eyebrows on Capitol Hill.

Long an outspoken ally of Trump’s, Gaetz was the subject of an ongoing ethics investigation in the House of Representatives into allegations of sexual misconduct, illicit drug use and misuse of campaign funds.

Senator Dick Durbin, the sitting chairman of the Senate Judiciary Committee, has asked for the findings of the report into the allegations to be published.

Gaetz is also divisive figure within his party after he forced out House Speaker Kevin McCarthy last year. Lisa Murkowski, a moderate Senate Republican, said Gaetz was not “a serious nomination for the attorney general”.

Meanwhile, Trump offered new details on the role Elon Musk will play in his administration, in his first public address since his election night victory speech.

The president-elect said Musk’s new Department of Government Efficiency would issue a series of reports in the coming weeks to streamline the US government.