What is Paxlovid Rebound?

Joe Gastaldo, MD, System Medical Director for Infectious Disease, explains the phenomenon known as Paxlovid rebound. 

We’ve been using Paxlovid for at risk people with COVID since early 2022. In the clinical trial, there was a phenomenon described as viral rebound. 

It basically boils down to this: people who have COVID get Paxlovid and they feel better. Approximately five to seven days after receiving Paxlovid, their symptoms return, and they’re found to have a rebound with a high viral load. Of note, that also took place in people who receive the placebo, and we have seen that, too, in people who have COVID 19. 

Now that we are prescribing more Paxlovid, this phenomenon is being reported more so, both with Pfizer and the FDA. This is what we know; it’s not associated with a reinfection. It doesn’t mean Paxlovid does not work. People who had the viral rebound have all done well and have not required hospitalization. 

It’s an area where we need to gather data. But, officially speaking, the FDA still recommends that people only be treated with a five day course and there’s no current need to extend or to give another five day course.

Want to learn more about common COVID-19 questions? Check our Fast Facts page.