Paxlovid is an anti-viral treatment for adults who are at risk of becoming seriously ill if they get COVID-19. It combines two antiviral drugs, nirmatrelvir and ritonavir and is a course of tablets taken over 5 days and should be started within 5 to 7 days of testing COVID-19 positive.
Paxlovid rebound describes a situation where people who are treated with Paxlovid recover and start testing negative, but then the COVID-19 infection comes back – or rebounds – after a few days or weeks. This can mean either the symptoms of COVID-19 come back, or people test positive for COVID-19 again, or both. It is worth noting that COVID-19 rebound can also happen when people haven’t received any COVID-19 treatment and, as yet, there is no published research to confirm that rebound rates are higher for people who take Paxlovid than for people who have no treatment.
Researchers don’t fully understand why Paxlovid rebound happens, but they are looking at possible causes, such as a resurgence of the virus, a secondary infection, or how the body’s immune system responds to the virus.
News about Paxlovid rebound has made some people worried about taking Paxlovid but it is important to consider the potential benefits:
- There is good evidence that Paxlovid significantly lowers your risk of getting seriously ill or dying from COVID-19. This is still true if you experience rebound after taking it.
- You may not have any symptoms with Paxlovid rebound, and if you do get symptoms, they are likely to be mild. Very few cases of serious symptoms have been reported.
It is thought that rebound may be avoided in future by extending the course of tablets, but there is no published evidence to support this yet. The manufacturer of Paxlovid, Pfizer, is conducting a trial to investigate this. The results are expected in September 2023.
What should I do if I have Paxlovid rebound?
If you have taken Paxlovid to treat COVID-19 and think you may have Paxlovid rebound:
- Tell your hospital team or GP – whoever takes the lead on your providing care for your immunodeficiency.
- Report what’s happened to the MHRA (Medicines & Healthcare products Regulatory Agency) via the Coronavirus Yellow Card scheme – this will help them monitor the extent of Paxlovid rebound amongst people who take it.
- Self-isolate for 5 days, as you may be infectious even if you have no symptoms.
February 2023. This page was reviewed by Dr Matthew Buckland, Chair of Medical Advisory Panel.