Fauci, 81, has served at NIAID for 38 years starting in former President Ronald Reagan’s administration, a role in which he helped lead the US response to the HIV/AIDS epidemic, as well as West Nile virus, the anthrax attacks, pandemic influenza, various bird influenza threats, Ebola and Zika. He became one of the most public faces of the federal response to the Covid-19 pandemic in 2020.