“The president has experienced no reemergence of symptoms and continues to feel quite well,” Dr. Kevin O’Connor, the White House physician, said in a memo released by the press office. “This being the case, there is no reason to reinitiate treatment at this time, but we will obviously continue close observation.”
The “‘rebound’ positivity,” as O’Connor termed it, meant that Biden was forced to resume “strict isolation procedures,” in keeping with medical advice. The White House announced that the president would no longer travel to his home in Wilmington, Delaware, on Sunday as planned or make a scheduled visit to Michigan on Tuesday.
Biden played down the development. “Folks, today I tested positive for Covid again,” he wrote 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.”
Biden first tested positive for Covid-19 on July 21 and experienced a sore throat, runny nose, cough, body aches and fatigue. After five days of isolation, he tested negative Tuesday evening and returned to the Oval Office on Wednesday.
But doctors were watching for signs of a rebound case and made sure to keep testing him every day. He tested negative Wednesday, Thursday and Friday before receiving a positive antigen result Saturday.
Paxlovid rebound has become a source of debate within the scientific community and among Covid-19 patients. Initial clinical studies of the drug, which is made by Pfizer, suggested that about 1% to 2% of those treated with Paxlovid experienced symptoms again. A study published in June that has not yet been peer-reviewed found that of 13,644 adults, about 5% tested positive again within 30 days and 6% experienced symptoms again.
“While we continue to monitor real-world data, we remain very confident in the treatment’s effectiveness at preventing severe outcomes from Covid-19,” Amy Rose, a Pfizer spokesperson, said in a statement Saturday.