When Dr. Anthony Fauci got COVID-19 in June, he took Paxlovid, an antiviral drug for people with mild to moderate symptoms whose immune statuses or ages put them at high risk for severe disease. The said treatment consists of three pills that are taken twice daily for five days, according to Yale Medicine.
Fauci finished the Paxlovid treatment and tested negative for COVID-19. However, a test returned positive about three days later, with his symptoms - sore throat, fever, and runny nose resurfacing. A small minority of people who take Paxlovid have seen a similar rebound effect.
Fauci, President Joe Biden's chief medical adviser and Director of the National Institute of Allergy and Infectious Diseases, said in an interview on Tuesday that rebound cases generally do not occur very often based on the studies. Fauci did note that there have been anecdotal cases that suggest COVID rebounds are more common now than they were in clinical trials.
Rebound rates about 5 percent of people who have taken Paxlovid
Around 1 to 2 percent of people taking Paxlovid in Pfizer's clinical trial tested positive for COVID-19 after having tested negative. Dr. Ashish Jha, the White House Covid response coordinator, said at a news conference last week that rebound rates are around 5 percent among the tens of thousands of people who have taken the drug in real-life settings.
Jha said that if you look at Twitter, it feels like everybody has a rebound, but there is clinical data. A small study conducted in June found that less than 1 percent of COVID-19 patients had their symptoms rebound around nine days, on average, after they took the drug Paxlovid.
In a larger study of 13,600 COVID patients, which has not been peer-reviewed, 6 percent had their symptoms rebound in the month following the said treatment. Dr. Aditya Shah, an infectious disease specialist at the Mayo Clinic, was the one who led the small study. He said that it is difficult for people to self-diagnose rebound cases. He added that ideally, people would have proof that they tested positive for COVID-19, then negative, then positive again for the coronavirus.
Health experts suspect the Paxlovid treatment regimen is too short
According to Shah, the actual number of rebound cases could be as high as 5 to 10 percent, but he does not think it is as common as the general community is making it out to be. The Centers for Disease Control and Prevention (CDC) said in May that symptoms usually rebound two to eight days after Paxlovid treatment is stopped if they come back at all.
Some disease experts suspect that the Paxlovid regimen is too short to clear the coronavirus in certain people. Dr. Peter Gulick, an associate professor of medicine at Michigan State University, told NBC News that one of the theories is that the sick person's natural immunity just can't kick in quickly enough.
