What To Know About Paxlovid's COVID-19 Rebound Cases

Paxlovid is Pfizer's oral antiviral drug for treating severe symptoms of COVID-19. It has been used in the U.S. since December, after the Food and Drug Administration (FDA) approved it for emergency use for people with mild to moderate cases who are at risk for developing a severe case of the illness. High risk includes people who are older, obese, pregnant, or have other health conditions such as diabetes or cancer, among other things (via NBC News).

On Thursday, the Centers for Disease Control and Prevention (CDC) issued a health advisory explaining that people who have taken the drug may experience a "rebound" case of COVID-19 even after their symptoms disappear and they test negative. Rebound cases have been reported anywhere from two to eight days after first recovering. The organization explained that a "brief return of symptoms may be part of the natural history" of COVID-19 in some people "independent of treatment with Paxlovid and regardless of vaccination status."

While research is limited, the CDC noted that people treated with Paxlovid who did experience a rebound had "mild" cases, adding that there is no reason to believe that additional treatment with the drug was necessary. The organization also reports that the median length of a COVID-19 rebound was about three days.

Experts claim that rebound cases after taking Paxlovid do not mean the drug isn't effective, according to NBC News. Clinical trials showed the drug lowered the risk of death and hospitalization of COVID-19 by 88% when taken within five days of symptoms starting. In addition, the drug remains on the National Institutes of Health's list of recommended drugs for people over the age of 12 that are considered high risk.

The CDC recommends that anyone experiencing rebound symptoms follow standard guidelines to prevent spreading the virus, including isolating and wearing a mask. You should also let your doctor know if your rebound symptoms become worse.