FILE - Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, responds to accusations by Sen. Rand Paul, R-Ky., as he testifies before the Senate Health, Education, Labor, and Pensions Committee about the origin of COVID-19, on Capitol Hill in Washington, July 20, 2021. Fauci, the nation's top infectious disease expert who became a household name, and the subject of partisan attacks, during the COVID-19 pandemic, announced Monday he will depart the federal government in December after more than 5 decades of service. (AP Photo/J. Scott Applewhite, Pool, File)