WASHINGTON — Days after ending his COVID-19 isolation, President Joe Biden has tested positive for the virus again, his physician said Saturday.
Biden's treatment included a five-day course of Paxlovid, an antiviral drug used to treat COVID-19 that has helped prevent more severe illness. His physician said Biden is one of a small percentage of Paxlovid patients who "rebound" and test positive again.
"After testing negative on Tuesday evening, Wednesday morning, Thursday morning and Friday morning, the President tested positive late Saturday morning, by antigen testing," wrote Dr. Kevin O'Connor in a letter. "This in fact represents 'rebound' positivity."
O'Connor said Biden is not experiencing symptoms and feels "quite well," so his health care team is not restarting treatment.
"Folks, today I tested positive for COVID again," Biden said on Twitter. "This happens with a small minority of folks. I’ve got no symptoms but I am going to isolate for the safety of everyone around me. I’m still at work, and will be back on the road soon."
Regulators are still studying rebound cases, but the CDC in May warned doctors that it has been reported to occur within two days to eight days after initially testing negative for the virus.
“Limited information currently available from case reports suggests that persons treated with Paxlovid who experience COVID-19 rebound have had mild illness; there are no reports of severe disease,” the agency said at the time.
White House COVID-19 coordinator Dr. Ashish Jha told reporters on Monday that “the clinical data suggests that between 5 and 8 percent of people have rebound” after Paxlovid treatment.
U.S. health officials have encouraged those who test positive to consult their doctors or pharmacists to see if they should be prescribed the treatment, despite the rebound risk.
Biden is fully vaccinated and has received two booster doses. He was diagnosed with the highly transmissible BA.5 variant of COVID, but had a mild bout with the virus. O'Connor consistently wrote in his updates that Biden's vital signs remained strong, and his temperature only became briefly elevated. He suffered from a runny nose, cough, sore throat and some body aches.
However, the infection was disruptive. Biden cancelled a trip to Pennsylvania, where he was going to detail his crime prevention plans and speak at at a Democratic National Committee fundraiser, and skipped a long weekend at his family home in Delaware.
First lady Jill Biden went without him, and Biden isolated in the White House residence. With voters already concerned about Biden’s age — he turns 80 in November — his aides emphasized that he was working despite his illness.
Biden's positive test Saturday is also disrupting his itinerary. He was scheduled for a trip to Michigan Tuesday to highlight the passage of a bill to promote domestic high-tech manufacturing. He was also set to visit Jill Biden in Delaware Sunday.