Intended for healthcare professionals


Sixty seconds on . . . covid rebound

BMJ 2022; 377 doi: (Published 30 May 2022) Cite this as: BMJ 2022;377:o1365
  1. Elisabeth Mahase
  1. The BMJ

Are we talking about bouncing back from covid?

Yes and no. Some patients seem to be getting better and even testing negative for SARS-CoV-2 before then experiencing a recurrence of symptoms and retesting positive two to eight days later. The phenomenon has been termed “covid rebound.”

Is this the same as paxlovid rebound?

Yes, although the US Centers for Disease Control and Prevention (CDC) has said that while many of the reports are of people taking a five day course of the antiviral paxlovid—which is used to prevent severe illness in newly infected at-risk patients—rebound has also been seen in those not taking the drug and seems to affect both those who are unvaccinated and vaccinated.1

Do people get better again?

So far there have been no reports of severe illness in those who have experienced covid rebound, and most people seem to recover and stop testing positive around three days later without needing additional covid-19 treatment.

Was this picked up in the paxlovid trial?

The trial did see a small number of participants test positive again shortly after testing negative and some who had an increase in the amount of SARS-CoV-2 detected by polymerase chain reaction test after completing their treatment course. Interestingly, however, this rebound effect was seen in both the paxlovid and placebo groups. “A brief return of symptoms may be part of the natural history of SARS-CoV-2 infection in some people, independent of treatment with paxlovid and regardless of vaccination status,” the CDC said.

Could these be cases of reinfection?

Based on the current evidence, the CDC said that these do not seem to be cases of reinfection. It noted, however, that during the rebound period it’s possible that people are infectious. As such, patients have been advised to re-isolate for at least five days if they experience a return of symptoms or test positive again.

That can’t be welcome news

The instruction to reisolate certainly has some doctors and patients reconsidering the antiviral, but the guidance has not changed and paxlovid continues to be recommended in the US for early treatment of mild to moderate covid-19 among at-risk people.

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