This phenomenon is known as Paxlovid rebound. What is it exactly, and why does it happen? How common is it, and does the possibility of a recurrence of symptoms mean that people shouldn’t take it? Who should and shouldn’t take the drug? And what should you do if you do have a recurrence?
Dr. Leana Wen: The phenomenon known as Paxlovid rebound is what happens when someone with Covid-19 takes the antiviral pill Paxlovid and begins to recover — their symptoms improve, and they start testing negative. Then, usually within two weeks of their initial diagnosis, they have a recurrence in their symptoms, and they test positive for the coronavirus again. In President Joe Biden’s case, he was being tested regularly, so even though his symptoms didn’t recur, his positive test was picked up right away.
Paxlovid works to stop viral replication. It is currently given for five days. Perhaps it works for the five-day period, but some people still have virus in their body after five days. When Paxlovid is stopped, the virus starts replicating again.
It’s possible that Paxlovid may need to be given for a longer period of time — maybe seven or 10 days instead of five days. Those studies are ongoing.
CNN: It seems like a lot of people have Paxlovid rebound, including President Biden and Dr. Anthony Fauci. How common is it?
Wen: Anecdotally, we may know a lot of people who’ve had it, but studies show that it’s pretty uncommon.
Of course, the actual rate may be higher, because people are not routinely being tested after they take Paxlovid. Some cases may be missed as a result. However, it still seems that Paxlovid rebound is occurring in a minority, not majority, of cases.
CNN: Does the possibility of a recurrence of symptoms mean that people shouldn’t take it?
Wen: No. I think people should consider the possibility of Paxlovid rebound like a known side effect of the medication. It’s certainly not preferred to have this, given the inconvenience of having repeat symptoms and having to isolate again. However, the possibility of this side effect is not a reason to avoid a medication that is highly effective at reducing severe illness.
CNN: Who is eligible for Paxlovid? Are there people who shouldn’t take it?
As far as people who shouldn’t take it, Paxlovid is intended for individuals at high risk for severe disease. If you are under 50, up to date with vaccines and generally healthy, you should not take it. Every medication is about weighing risks and benefits. If you are unlikely to benefit, the risks will outweigh the benefits.
CNN: What should you do if you do have a recurrence — do you take Paxlovid again, and do you need to isolate?
Using caution is the right approach, but I want to emphasize again that the possibility of rebound should not dissuade people from taking a treatment that is doing what it should, which is to keep people out of the hospital and preventing them from getting severely ill.