WASHINGTON – President Biden finally tested negative for the coronavirus on Saturday, a week after his rebound case emerged, but the White House physician said the president would remain in isolation “out of an abundance of caution” pending another negative test.
Mr. Biden has stayed away from the Oval Office since he tested positive again on July 30, although he has tried to maintain a public presence through video appearances from the White House residence. The recurrence of the virus has kept him off the road for political events and also delayed summer vacation plans.
The president has experienced few symptoms during his rebound case, according to Dr. Kevin C. O’Connor, the White House physician, and he appeared in relatively good health in his video events over the past few days. “The president continues to do very well,” said Dr. O’Connor in a note released to reporters on Saturday.
Throughout the President’s initial battle with Covid-19 and during his rebound case, Dr. O’Connor never appeared before reporters to answer questions, unlike previous White House physicians under other presidents. The White House has never given a clear explanation as to why. Dr. O’Connor’s daily notes have not yielded any theories about where or how the president became infected. White House officials have said that those believed to have been in close contact with Mr. Biden, all tested negative.
The president was treated with Paxlovid early in his battle with Covid, and while the drug has been credited with great success in suppressing the virus and preventing severe cases and hospitalizations, a number of patients who have taken it have nevertheless tested positive again a few days later the last dose of the five-day regimen.
Initial clinical studies showed that only about 1 percent to 2 percent of those treated with Paxlovid, which is made by Pfizer, experienced symptoms again. Subsequent studies of patients have found higher rates, although still in the single digits.
But some doctors and patients have speculated that the rebound rate could be even higher because of anecdotal experience and because of the properties of the highly contagious Omicron subvariants in circulation this summer. Among those who have had a rebound case after taking Paxlovid were Dr. Anthony S. Fauci, the president’s chief medical adviser and a leading figure in the response to the pandemic.
Sir. Biden has been described by aides as eager to get out of isolation and back on the road as the midterm congressional campaign begins to heat up. As a result of his infection, he has had to cancel a number of planned trips and has limited his contact with aides, advisers and others at a time when he has scored some important victories that he wants to promote.
“I wish I was with you in person, quite frankly,” he told Vice President Kamala Harris and several cabinet members over a video feed during an event Wednesday where he outlined his plans to take steps to protect abortion rights. “But I’ll get there.”