President Donald Trump will nominate Dr. Susan Monarez, the acting director of the U.S. Centers for Disease Control and Prevention, to the job, a White House official confirmed Monday.

Trump abruptly withdrew the nomination of his first pick, David Weldon, earlier this month.

Monarez has been serving as the CDC’s acting director since January. She came from an outside federal government agency, the Advanced Research Projects Agency for Health.

Earlier this month, the White House withdrew the nomination of Weldon, a former Florida congressman, to lead the CDC. Weldon told the media his nomination was withdrawn because “there were not enough votes to get me confirmed.”

Weldon was closely aligned with Robert F. Kennedy Jr., the U.S. health secretary who for years has been one of the nation’s leading anti-vaccine activists.

The CDC is based in Atlanta and has a $9.2 billion core budget. It 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