Anthony Fauci will step down from his positions in the Biden administration in December.

Fauci, the chief medical adviser to the president and longtime director of the National Institute of Allergy and Infectious Diseases, said he will be leaving those positions to “pursue the next chapter in my career.”

“While I am moving on from my current positions, I am not retiring,” Fauci said in a statement Monday. “After more than 50 years of government service, I plan to pursue the next phase of my career while I still have so much energy and passion for my field. I want to use what I have learned as NIAID Director to continue to advance science and public health and to inspire and mentor the next generation of scientific leaders as they help prepare the world to face future infectious disease threats.”