Covid ‘Rebound’ after Paxlovid


According to updates, Pres. Biden is reportedly testing positive for Covid-19 for straight seven days after his ‘rebound’ infection. Quoting White House physician Dr. O’Connor, The Hill writes “Biden ‘continues to feel very well‘ despite his rebound COVID-19 infection. Such rebound infections have been seen in some patients who take the antiviral treatment Paxlovid.

In this The Conversion magazine article, Lara Herrero, Research Leader in Virology and Infectious Disease, Griffith University, discusses “Why do some people who take Paxlovid for COVID get ‘rebound’ symptoms? Or test positive again, like President Biden?

Here is what Lara Herrero describes about Paxlovid:

  • Paxlovid is a combination treatment that uses two different antivirals: nirmatrelvir and ritonavir.
  • Nirmatrelvir works to prevent the virus replicating. It does this by stopping a viral enzyme called a protease.
  • Ritonavir is a “boosting agent” which prevents the metabolism of nirmatrelvir, meaning it stays in your system for longer.

Therefore, Paxlovid stops creating new “active” virus particles being made but does not kill the already existing virus particles, which explains why some people even after Paxlovid treatment get tested positive for Covid-19.

However, the drug is effective reducing the risk of hospitalization and there reportedly no reported death after Paxlovid treatment.

What is Rebound?

The article explains “rebound” as “when a person appears to have recovered and ‘cleared‘ the virus, meaning they test negative on the very sensitive PCR test and have no symptoms. Then a few days later, they test positive again or symptoms return. Rebound is not specific to people who have taken Paxlovid – it can also happen to others with COVID who didn’t receive any drug treatments.”

“If your goal is to prevent severe disease, hospitalisation and death in high-risk people, then Paxlovid is doing a great job. However, if you want to shorten the duration of your symptoms, maybe Paxlovid isn’t the wonder drug we hoped for,” writes Herrero.