White House Doctor: Biden 'Unsurprisingly' Still COVID-Positive in 'Rebound' Case

President Joe Biden speaks to the press after taking part in a working session with Saudi Arabia's crown prince at the Al-Salam Palace in Jeddah, on July 15, 2022. (Mandel Ngan/AFP via Getty Images)

President Joe Biden "unsurprisingly" tested positive again for COVID-19 on Sunday but "continues to feel" well after he tested positive again over the weekend, according to his doctor in a letter issued on Sunday.

"The President will continue his strict isolation measures as previously described," White House doctor Kevin O'Connor wrote (pdf). "He will continue to conduct the business of the American people from the Executive Residence."

“As I have stated previously, the president continues to be very specifically conscientious to protect any of the Executive Residence, White House, Secret Service, and other staff whose duties require (albeit socially distanced) proximity to him,” the physician wrote Sunday.

Biden tested positive for COVID-19 less than two weeks ago and began taking Pfizer-made Paxlovid, according to the doctor. He received a negative test on Tuesday and ended his quarantine,  but on Saturday, O'Connor said he tested positive again although he has no symptoms.

Right after he tested negative on July 26, Biden gave remarks at the White House Rose Garden on July 27. Because of his advanced age, Biden is at risk of developing severe COVID-19, although a letter (pdf) from his physician on July 23  indicated that the president suffered mild symptoms.

Paxlovid

On Saturday, O'Connor said that Biden was among the "small percentage" of people taking Paxlovid who had a "rebound" of COVID-19 symptoms. Among other notable "COVID rebound" cases is White House adviser Anthony Fauci, who said he took Paxlovid, tested negative for several consecutive days for COVID-19, and later returned a positive test.

Earlier this year, the U.S. Centers for Disease Control and Prevention issued an alert about COVID-19 rebound cases associated with Paxlovid.

“Paxlovid continues to be recommended for early-stage treatment of mild to moderate COVID-19 among persons at high risk for progression to severe disease,” said the agency in a notice. “Paxlovid treatment helps prevent hospitalization and death due to COVID-19. COVID-19 rebound has been reported to occur between 2 and 8 days after initial recovery and is characterized by a recurrence of COVID-19 symptoms or a new positive viral test after having tested negative.”

After Biden's second COVID-19, some scientists questioned the official data around Paxlovid, with one even suggesting that the number of rebound cases is around 40 percent—far higher than the 2 percent claimed by Pfizer.

“The prior data suggesting ‘rebound’ Paxlovid positivity in the low single digits is outdate[d] and with BA.5 is likely 20-40 percent or even higher,” posted Dr. Jonathan Reiner, a prominent cardiologist and professor of medicine at George Washington University Hospital, on July 30.