US President-elect Donald Trump has vowed to nominate anti-vaccine activist Robert F Kennedy Jnr to lead the Department of Health and Human Services.

The decision will put a man whose views public health officials have decried as dangerous in charge of a massive agency that oversees everything from drug, vaccine and food safety to medical research and the Medicare and Medicaid schemes.

“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,” Mr Trump wrote on his Truth Social site as he announced the appointment on Thursday.

Mr Kennedy, he claimed, would “end the chronic disease epidemic" and “make America great and healthy again!” adding that he would target drugs, food additives and chemicals.

As one of the world's most prominent vaccine opponents, Mr Kennedy's nomination immediately alarmed some public health officials.

US Centre for Disease Control and Prevention director Dr Mandy Cohen told the Associated Press news agency: “I don’t want to go backwards and see children or adults suffer or lose their lives to remind us that vaccines work and so I am concerned.”