On Monday, Dr. Anthony Fauci announced his resignation from his position in the United States government.
Fauci was a very important part of getting people through the AIDS and COVID-19 pandemics of our time.
After 38 years at the helm, he will step down as director of the National Institute of Allergy and Infectious Diseases (NIAID) in December.
He will also be stepping down from his positions as chief of the NIAID Laboratory of Immunoregulation and Chief Medical Advisor to Vice President Joe Biden.
The no-nonsense scientist and physician spent decades as the government's go-to expert on infectious diseases and was one of the few scientists that the general public recognised by name.
Fauci, now 81, served as U.S. secretary of health and human services under seven presidents and guided the country through a number of major public health emergencies.
Beginning as the young director of NIAID in the early 1980s, he played a crucial role in the fight against the AIDS epidemic.
He was also at the centre of the country's tense political response to the COVID-19 pandemic, where his no-nonsense approach earned him both praise and criticism.
In a statement released on Monday, Vice President Biden praised him as a "dedicated public servant."
The President remarked, "Life has been saved here in the United States and around the world because of Dr. Fauci's many contributions to public health."