NEW YORK >> Dr. David Weldon had been out of the national spotlight for more than 15 years when he was nominated to head the Centers for Disease Control and Prevention. But many anti-vaccine advocates knew him well.

“He is one of us!! Since before our movement had momentum,” the co-director of Mississippi Parents for Vaccine Rights wrote on Facebook. And on X, formerly known as Twitter, the Autism Action Network credited the former congressman with introducing legislation two decades ago “to stop the vaccine pedocide.”

Weldon, who was nominated by President Donald Trump, needs to be confirmed by the U.S. Senate before he can lead the nation’s top public health agency. His confirmation hearing is to be held Thursday.

The 71-year-old retired Florida congressman is considered to be closely aligned with his presumptive boss, Robert F. Kennedy Jr., the U.S. health secretary who for years has been one of the nation’s leading anti-vaccine activists.

Department of Health and Human Services officials declined to make Weldon or Kennedy available for an Associated Press interview.

When he made the nomination announcement, Trump said Weldon “will proudly restore the CDC to its true purpose, and will work to end the Chronic Disease Epidemic, and Make America Healthy Again!”

The CDC was created nearly 80 years ago to prevent the spread of malaria in the U.S. Its mission was later expanded, and it gradually became a global leader on infectious and chronic diseases and a go-to source of health information.

Today, the Atlanta-based agency has a more than $9 billion core budget. It had about 13,000 employees when Trump took office, but more than 500 were fired as part of a dramatic — and continuing — push by the president and his billionaire adviser Elon Musk to cut staffing across federal agencies.

Weldon has no experience in federal public heath, but that isn’t unusual. The last few presidential administrations — both Democratic and Republican — have appointed outsiders with no CDC experience.

Unlike Weldon, however, those outsiders had been public health researchers or had run state health departments. He is an Army veteran and internal medicine doctor whose main claim to fame was representing a central Florida district in Congress from 1995 to 2009.

After he left Congress, Weldon practiced medicine in Florida, taught at the Florida Institute of Technology, served as board chairman for the Israel Allies Foundation and made unsuccessful runs at federal and state elected office. In a March 1 letter to HHS, Weldon said that if confirmed he will resign from the foundation and from two Florida health-care organizations. He also promised to sell his holdings in funds investing in energy, pharmaceutical and health-care companies.

Weldon was a leader of a Congressional push for research into autism’s causes, which began around 2000. It was fueled by a controversial — and ultimately discredited — study by British researcher Dr. Andrew Wakefield that claimed to find a link between the measles-mumps-rubella vaccine and autism.

The action in Congress was driven largely by U.S. Rep. Dan Burton, an Indiana Republican whose grandson had autism. Weldon was a prominent voice in Burton’s hearings and co-sponsored a bill that would give responsibility for the nation’s vaccine safety to an independent agency within HHS — an idea that not everyone in public health opposes.

But Weldon also rejected studies that found no causal link between childhood vaccines and autism, and accused the CDC of short-circuiting research that might show otherwise.