Jill Biden, 71, began to develop cold-like symptoms on Monday evening and a PCR test came back positive, according to the spokesperson.
Double-vaccinated and twice boosted, Jill Biden is "only experiencing mild symptoms" and has been prescribed a course of Paxlovid, an antiviral therapy produced by Pfizer and given to patients with COVID-19.
The U.S. first lady, the spokesperson added, will isolate for at least five days.
She is currently staying at a private residence in South Carolina and will return home after she receives two consecutive negative tests.
More about: United-States coronavirus