President Joe Biden has tested negative for COVID-19 after testing positive with a breakthrough case for days, the White House physician said on Saturday. 

The Democratic president will remain in isolation until he tests negative on a second test, Dr. Kevin O’Connor said in a letter. 

Biden, 79, emerged from isolation on Wednesday after testing positive for COVID-19 for the first time on July 21. He tested positive again on July 30 in what O’Connor described as a “rebound” case seen in a small percentage of people who take the antiviral drug Paxlovid.