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.

Weldon has questioned the safety of some vaccines and advocated for limits on abortion. He'll be the first CDC director to face Senate confirmation.

While in Congress, Weldon introduced a bill that would give responsibility for the nation's vaccine safety to an independent agency within the HHS.