Three members of the White House coronavirus task force are self-isolating for two weeks after possible exposure to the illness.
Dr Anthony Fauci, who has become the public face of the fight against the virus in the US, is one of those who will go into quarantine.
His agency, the National Institute of Allergy and Infectious Diseases, said he was at “relatively low risk” due to the degree of his exposure.
Dr Fauci has tested negative.
The 79-year-old will work from home for the time being and will be regularly tested, the institute said.
Her diagnosis came after a valet for US President Donald Trump was also confirmed to have the illness.