Dr. Kevin O’Connor said Biden has been in daily monitoring during isolation and continues to improve.
“In an abundance of caution, the president will continue his strict isolation measures pending a second negative test as previously described,” O’Connor said in a statement Saturday morning.
Biden, who has received two vaccine boosters, first tested positive on July 21, when he was experiencing mild symptoms such as a sore throat and body aches.
His symptoms improved after treatment with the antiviral Paxlovid, and the president tested negative July 27.
Three days later, he once again tested positive, in a rare case of rebound infection that one study has shown to affect 0.8 percent of people treated with the antiviral.
Biden has maintained his presence through video appearances from isolation.
“Keep the faith,” he said in one of them on July 21. “It’s going to be OK.”