Dr. Anthony Fauci, chief medical advisor to President Joe Biden, has tested positive for COVID-19.
According to a statement from the agency he leads, the National Institute of Allergy and Infectious Diseases (NIAID), Fauci is experiencing mild symptoms.
"He is fully vaccinated and has been boosted twice," the statement says.
The 81-year-old plans to isolate and work from home until he tests negative.
The statement says Fauci has not recently been in close contact with Biden.
Fauci has been at the forefront of the COVID-19 pandemic since the beginning. He served on the COVID-19 Task Force under then-President Donald Trump. Fauci built a reputation for countering Trump when he felt like bad information about the virus was being released.
Fauci is not without controversy. Many Republicans view him as inconsistent and they are not in favor of restrictions he has touted in an attempt to get a handle on the virus.
Fauci told CNN recently he would not work for Trump again if the former president won another term in the White House.