Dr. Anthony Fauci is the nation's top infectious disease expert

He will leave the federal government in December after five decades of service.

Fauci is the chief medical advisor to the president.

He was the director of the NIAID laboratory.

Dr. Fauci was a leader in the federal response to HIV/AIDS and other infectious diseases

Fauci said in a statement that he will be leaving his positions in December of this year to pursue the next chapter of his career

Fauci has touched the lives of all Americans with his work, according to Joe Biden.

Fauci said he would continue working despite retiring from federal service.

He said, "I want to use what I have learned as NIAID Director to continue to advance science and public health."