The Senate has confirmed Robert F Kennedy Jr as President Donald Trump’s health secretary.

The approval puts the prominent vaccine sceptic in control of 1.7 trillion dollars of federal spending, vaccine recommendations and food safety as well as health insurance programmes for roughly half the country.

Republicans fell in line behind Mr Trump despite hesitancy over Mr Kennedy’s views on vaccines, voting 52-48 to elevate the scion of one of America’s most famous political — and Democratic — families to secretary of the Health and Human Services Department.

Robert F Kennedy Jr is a vaccine sceptic (J. Scott Applewhite/AP)

Kentucky Senator Mitch McConnell, who had polio as a child, was the only “no” vote among Republicans, mirroring his stands against Mr Trump’s picks for the Pentagon chief and director of national intelligence. All Democrats opposed Mr Kennedy.

The Republican party has largely embraced Mr Kennedy’s vision to “Make America Healthy Again” by directing the public health agencies to focus on chronic diseases such as obesity.

Mr Kennedy, 71, whose name and family tragedies have put him in the national spotlight since he was a child, has earned a formidable following with his populist and sometimes extreme views on food, chemicals and vaccines.

His audience grew during the Covid-19 pandemic, when he devoted much of his time to a non-profit that sued vaccine makers and harnessed social media campaigns to erode trust in vaccines as well as the government agencies that promote them.

With Mr Trump’s backing, Mr Kennedy insisted he was “uniquely positioned” to revive trust in those public health agencies, which include the Food and Drug Administration, the Centres for Disease Control and Prevention, and the National Institutes for Health.

President Donald Trump has been criticised by Democrats (Alex Brandon)

Last week, Senator Thom Tillis said he hoped Mr Kennedy “goes wild” in reining in health care costs and improving Americans’ health.

But before agreeing to support Mr Kennedy, Republican Bill Cassidy, a doctor who leads the Senate Health, Education, Labour and Pensions Committee, required assurances that Mr Kennedy would not make changes to existing vaccine recommendations.

During Senate hearings, Democrats tried to prod Mr Kennedy to deny a long-discredited theory that vaccines cause autism. Some lawmakers also raised alarms about Mr Kennedy financially benefiting from changing vaccine guidelines or weakening federal lawsuit protections against vaccine makers.

Mr Kennedy made more than 850,000 dollars last year from an arrangement referring clients to a law firm that has sued the makers of Gardasil, a human papillomavirus vaccine that protects against cervical cancer.

If confirmed as health secretary, he promised to reroute fees collected from the arrangement to his son.

Mr Kennedy will take over the agency in the midst of a massive federal government shakeup, led by billionaire Elon Musk, that has shut off — even if temporarily — billions of taxpayer dollars in public health funding and left thousands of federal workers unsure about their jobs.

On Friday, the NIH announced it would cap billions of dollars in medical research given to universities and cancer being used to develop treatments for diseases such as cancer and Alzheimer’s.