President Joe Biden again tested positive for COVID-19 on Monday due to a "rebound" of "positivity" sparked by the drug Paxlovid, according to his doctor in an update.
"Given his rebound positivity, which we reported Saturday, we continued daily monitoring," he said. "This morning, as could be anticipated, his SARS-CoV-2 antigen testing remained positive."
Biden, who has received four vaccine doses, will continue to be under strict isolation for now, O'Connor said.
Last week, the president briefly emerged from quarantine following a negative test, delivering remarks at the White House Rose Garden. The White House has not confirmed whether any staffers contracted COVID-19.
Per Centers for Disease Control and Prevention (CDC) guidelines, Biden has to quarantine for at least five days after testing positive for the virus.
COVID ReboundHealth officials and Pfizer have said Paxlovid rebound impacts a small number of recipients, although White House adviser Anthony Fauci also experienced it several weeks ago. Fauci confirmed that he tested negative for four days before testing positive as he took the drug, which was first handed an emergency use authorization by the Food and Drug Administration in late 2021.
“If you look at Twitter, it feels like everybody has rebound,” Jha said. “But it turns out there’s actually clinical data.”
But with Biden's recurrent positive test, some scientists have speculated that data showing only a small number of Paxlovd recipients experience the so-called "COVID rebound" is outdated.
Dr. Jonathan Reiner, a prominent cardiologist and professor of medicine at George Washington University Hospital, said in a Twitter post over the weekend that he believes that Pfizer-associated rebound cases are actually quite common.