Kiawah, South Carolina - First lady Jill Biden tested positive for the coronavirus while vacationing with her husband in South Carolina, the White House said on Tuesday.

A rapid antigen test was initially negative, but a PCR test came back positive. She will now isolate at the vacation home in Kiawah Island for at least five days and be treated with the antiviral drug Paxlovid.

The first lady, who is only experiencing mild symptoms, has been double vaccinated against the virus and received two booster shots.

President Joe Biden, who has just recovered from his own bout of Covid-19, which included a rebound infection, tested negative on Tuesday.

As a precaution, the White House said it would "increase the president's testing cadence and report those results." He will also be wearing a mask indoors and when coming into close contact with other people.

Biden is returning to Washington as planned on Tuesday to sign the Inflation Reduction Act, a sweeping new climate, health, and tax package.

He will mark the occasion with a ceremony at the White House scheduled to start at 3:30 PM EDT.