WASHINGTON — The Senate on Thursday confirmed Robert F. Kennedy Jr. as President Donald Trump’s health secretary, putting the prominent vaccine skeptic in control of $1.7 trillion in federal spending, vaccine recommendations and food safety as well as health insurance programs for roughly half the country.

Republicans fell in line behind Trump despite hesitancy over Kennedy views on vaccines, voting 52-48 to elevate the scion of one of America’s most storied political — and Democratic — families to secretary of the Health and Human Services Department. Kentucky Sen. Mitch McConnell, who had polio as a child, was the only “no” vote among Republicans, mirroring his stands against Trump’s picks for the Pentagon chief and director of national intelligence. All Democrats opposed Kennedy.

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

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 only grew during the COVID-19 pandemic, when Kennedy devoted much of his time to a nonprofit that sued vaccine makers and harnessed social media campaigns to erode trust in vaccines as well as the government agencies that promote them.

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

Last week, Sen. Thom Tillis, R-N.C., said he hoped Kennedy “goes wild” in reining in health care costs and improving Americans’ health. But before agreeing to support Kennedy, potential holdout Sen. Bill Cassidy, R-La., a doctor who leads the Senate Health, Education, Labor and Pensions Committee, required assurances that Kennedy would not make changes to existing vaccine recommendations.

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

Kennedy made more than $850,000 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.

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.

Kennedy, too, has called for a staffing overhaul at the NIH, FDA and CDC. Last year, he promised to fire 600 employees at the NIH, the nation’s largest funder of biomedical research.