Unlike President Trump's picks to lead other health agencies who established their conservative bona fides during the COVID-19 pandemic, his choice to head the CDC, Dave Weldon, was virtually invisible during that period. But an examination by STAT of thousands of pages of documents from Weldon's 14 years in Congress, part of his archives housed here at the Florida Institute of Technology, and interviews with a half-dozen former health officials, found that his support for anti-vaccine theories runs long and deep.