First lady Jill Biden tests positive for COVID-19 again, while president tests negative

First lady Jill Biden tested positive again for COVID-19, the White House announced Wednesday – just one day after she tested negative.

"After testing negative on Tuesday, just now, the First Lady has tested positive for COVID-19 by antigen testing," according to a statement issued by her deputy communications director, Kelsey Donohue. "This represents a 'rebound' positivity."

As a result, the first lady, who was supposed to return to the White House with the president on Wednesday, stayed behind in Delaware while he arrived alone on Marine One.

Previously: Jill Biden tests negative for COVID-19, plans to reunite with President Joe Biden

Donohue's statement said the first lady has experienced "no reemergence of symptoms," and will remain in Delaware where she was isolating again.

"The White House Medical Unit has conducted contact tracing and close contacts have been notified," the statement concluded.

Earlier, the White House announced the president tested negative for COVID-19 Wednesday morning on an antigen test.

As a close contact with his wife, he will mask for 10 days when indoors and in close proximity to others, the White House said, adding that his "testing cadence" will be increased.

Late Wednesday, the first lady posted a couple of pictures on her social media, of the family's grey cat Willow lounging on a blue-and-white striped deck chair at the Bidens' Delaware beach house.

"She won't leave my side!" Biden said in her tweet, adorned with red heart emojis.

The first lady, 71, had been dealing with COVID-19 issues since the couple's vacation in South Carolina, when she was forced to stay behind an extra five days isolating while he returned to Delaware and to Washington. The White House has said she experienced only mild symptoms of the virus.

The first positive: First lady Jill Biden tests positive for COVID-19

She first tested positive for the virus on Aug. 15, when she and the president and members of their family were vacationing in Kiawah Island, South Carolina. She isolated in the beach town until she received two negative tests and was cleared to meet the president at their Rehoboth Beach home in Delaware on Sunday.

After returning to Washington, the couple were to attend a fundraising event for the Democratic National Committee in nearby Montgomery County, Maryland, on Thursday, but that's now off, at least for her.

Like her husband, the first lady has been twice-vaccinated and twice-boosted with the Pfizer COVID-19 vaccine. She had been prescribed the antiviral drug Paxlovid, which has been effective at preventing serious disease and death among those at highest risk from COVID-19. But a minority of those prescribed the drug have experienced a rebound case of the virus a few days after their initial recovery.

Contributing: The Associated Press

This article originally appeared on USA TODAY: Jill Biden tests positive for COVID again, while POTUS tests negative