Weldon, 71, is a medical doctor and former lawmaker who served in the House, representing Florida. The former congressman has been a strong critic of the CDC, especially its vaccine program. Weldon has championed the long-debunked notion that thimerosal, a vaccine preservative, is linked to autism.

In selecting a doctor who is skeptical of vaccine safety, the president-elect is emphasizing his commitment to reforming the role of federal health agencies in radical ways.