The First Lady's communications director, Elizabeth Alexander, said a rapid antigen test was negative, although a more detailed PCR test was positive.
The official also said that Jill Biden, who "has two vaccinations, two boosters," is developing mild symptoms. She will receive the oral antiviral pill Paxlovid and remain in isolation for at least five days.
The First Lady tested positive during her vacation in South Carolina. According to her communications director, her return to the White House will come after two consecutive negative results.