Is Paxlovid Rebound Real? What to Do If COVID-19 Symptoms Return After Taking Medication
Key takeaways:
Paxlovid (nirmatrelvir / ritonavir) is an oral antiviral FDA approved to treat mild-to-moderate COVID-19 in certain people.
After finishing a course of Paxlovid, some people get better and then start having symptoms again. This has been referred to as “Paxlovid rebound.”
Rebound COVID symptoms are not a side effect of Paxlovid. This return of symptoms is also possible with other COVID treatments and in people who received no treatment in the first place.
COVID rebound symptoms after taking Paxlovid are typically mild and last for about a week for many people. There have been no reported hospitalizations or deaths due to COVID rebound.
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Table of contents
When it was first FDA authorized, Paxlovid (nirmatrelvir / ritonavir) was considered a game changer for treating COVID-19. With a 5-day course of this antiviral combination, people were feeling better and testing negative sooner than they would have without it. But after it became more readily available, a new term grew in popularity: Paxlovid rebound.
“Paxlovid rebound” has been coined to describe the return of COVID symptoms after a person has finished the medication. But even so, Paxlovid is still considered the first-choice medication for people at a high risk of developing severe COVID. So, is Paxlovid rebound a real side effect of the medication? In short, no. Let’s discuss more about COVID rebound symptoms and what to do if they happen to you.
What is considered a Paxlovid rebound?
The term “Paxlovid rebound” isn’t an official medical diagnosis. But it has come to describe a return of COVID symptoms (COVID rebound) after an individual has finished a 5-day course of Paxlovid.
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According to the CDC, this return of symptoms happens between 3 and 7 days after you initially recover. It could also be marked by a positive COVID test 3 to 7 days after receiving a negative test.
Paxlovid (COVID) rebound symptoms
Like COVID symptoms, the symptoms of rebound after taking Paxlovid may vary between people. But typically, your initial COVID symptoms will get better (or even go away) while taking Paxlovid. Then between 3 and 7 days after finishing the medication, your symptoms will get worse again.
COVID rebound symptoms you might experience could include:
Muscle aches
Fever or feeling feverish
Cough
Fatigue
Stuffy or runny nose
Sore throat
Chills
Is COVID rebound contagious?
Yes, COVID rebound after Paxlovid is likely contagious — even if it’s not causing symptoms. Getting a positive COVID test result means the COVID virus is present in your body. And you can transmit the virus to others.
How long does COVID rebound last, and is it worse than the previous infection?
COVID rebound after taking Paxlovid likely only lasts a few days, but research on the subject is limited. In December 2023, the CDC reported that COVID rebound lasted for roughly 7 days in studies. But these studies were very small. More research is needed to confirm this information.
COVID rebound after Paxlovid is typically mild. No hospitalizations or death due to rebound have been reported since the phenomenon first came to light.
Possible side effects: COVID rebound isn’t a Paxlovid side effect. Learn what side effects are linked to Paxlovid and how to manage them.
What it feels like to take Paxlovid: Three people share their experiences with Paxlovid, which can be beneficial for many people at high risk from COVID.
How fast does Paxlovid work? Get the answer to this and other frequently asked questions about Paxlovid.
How common is COVID rebound after finishing Paxlovid?
COVID rebound after Paxlovid is relatively common.
When Paxlovid was first granted emergency use authorization (EUA), Pfizer (Paxlovid’s manufacturer) reported that cases of COVID rebound happened to between 1% and 2% of people taking Paxlovid. These rates were similar to people who took a placebo (a pill with no medication in it) during clinical trials.
Data released in March 2023 showed COVID rebound after Paxlovid happened more often. Study results that Pfizer shared with the FDA suggest that rebound symptoms happened to between 10% and 16% of people taking Paxlovid.
A small, observational study from November 2023 found that about 1 in 5 people who had taken Paxlovid tested positive for COVID following a prior negative result. But researchers noted that many of them didn’t experience rebound symptoms. Keep in mind a positive test with or without symptoms is considered a form of COVID rebound.
Does COVID rebound mean that Paxlovid is not effective?
No, a COVID rebound doesn’t mean Paxlovid didn’t work.
Paxlovid doesn’t kill the virus that causes COVID. Think of it more like a pause button. It temporarily stops the virus from making copies of itself in your body. This allows your immune system to kill it more easily.
For people with risk factors for severe illness, this pause can help prevent serious complications. Paxlovid’s goal is to help stop you from going to the hospital or dying from COVID. Your immune system is what clears the infection.
As your immune system lowers the number of virus copies, your symptoms will improve. Once you stop taking Paxlovid, it’s like pressing play again. The virus goes back to copying itself. And this slight bump back up in virus copies can mean symptoms come back.
Does Paxlovid cause COVID rebound?
No, current data shows that Paxlovid doesn’t cause COVID rebound. This return of symptoms is likely just how some people’s immune systems fight and recover from the infection.
In an exclusive interview with GoodRx Health, Christina Madison, PharmD, founder and CEO of The Public Health Pharmacist, discussed why rebound symptoms seem to occur.
“COVID-19 rebound symptoms have occurred in both treated and untreated individuals,” said Madison. “The rebound effects that have been experienced by [people] who have taken Paxlovid seem to be based on how the body immune system responds to the infection, the ability of the medication to get to affected tissues, and viral reservoirs — and [it] is not considered a side effect of the medication.”
COVID rebound doesn’t only happen after taking Paxlovid either. A study of over 12,500 adults suggests that it also happens after treatment with Lagevrio (molnupiravir), another oral antiviral authorized for COVID. But because Paxlovid is the first-choice treatment for mild to moderate COVID, this phenomenon has been dubbed “Paxlovid rebound.”
When should you test for COVID after taking Paxlovid?
There’s no standard guidance on when to test for COVID after taking Paxlovid. In fact, the CDC no longer recommends retesting for COVID before returning to your usual activities.
It’s generally a good idea to stay home and away from others until you at least finish Paxlovid. But there are other things to look for. The CDC says you can return to your usual activities when:
Your symptoms are getting better overall, and
You’ve been fever-free for at least 24 hours and haven’t been taking fever reducers, such as Tylenol (acetaminophen)
It’s recommended to take extra steps to prevent spreading COVID to others for 5 days after returning to your usual activities. The CDC recommends things like wearing a face mask, washing your hands often, and distancing yourself from others when possible.
What should you do if you have a COVID rebound after taking Paxlovid?
If you have a COVID rebound after taking Paxlovid, stay home and away from others again. Follow the guidance above to determine when you can return to your usual activities. It’s also a good idea to report your case of rebound to Pfizer. This can help them continue to track and study how often it happens.
Who’s at risk for COVID rebound after taking Paxlovid?
Researchers are still trying to determine if some people have a higher risk of COVID rebound after taking Paxlovid than others. More studies are needed to confirm these risk factors.
A 2022 preprint study noticed some trends in people who experienced rebound symptoms after taking Paxlovid. Keep in mind more research is needed to verify if these are true risk factors. Study authors noted the following characteristics were seen more with COVID rebound cases:
People with medical conditions that raise the risk of severe COVID illness
People who had organ transplants
People who smoke
People who take medications that weaken the immune system
A 2024 study suggests that taking Paxlovid before you start feeling symptoms may raise your risk of COVID rebound. So you shouldn’t take the medication to help prevent COVID after being exposed to someone who’s sick.
How do you treat rebound COVID symptoms after taking Paxlovid?
There are no specific CDC recommendations on what to take for rebound COVID symptoms. Over-the-counter cold medications, like NyQuil and Theraflu, can help lessen certain symptoms for some people. But these medications won’t kill the virus that causes COVID.
If your symptoms become severe, you should contact your primary care provider or seek medical attention. They may suggest other medications based on your situation and medical history.
Should you take Paxlovid again if you experience COVID rebound?
No, at this time, taking Paxlovid again for rebound symptoms isn’t recommended by the CDC or FDA. Additionally, the CDC doesn’t recommend taking other COVID treatments, like Lagevrio, to treat rebound symptoms. Pfizer has finished a clinical trial exploring whether a second round of Paxlovid is effective for rebound symptoms. But the results of this study haven’t been published yet.
Can you have COVID rebound without Paxlovid? [Rebound without Paxlovid]
Yes, it’s possible to experience COVID rebound even if you took no medications. Pfizer’s studies have found that rebound rates were similar for people taking Paxlovid and a placebo. But other studies have reported that COVID rebound happened to about 30% of people who received no treatment.
Frequently asked questions
Paxlovid doesn’t directly affect how contagious you are. It stops the virus from multiplying in your body. This allows your immune system to kill the virus more easily. As your immune system clears the infection, you become less contagious over time.
Yes, Paxlovid may help shorten a COVID infection. One study found that people taking Paxlovid tested negative an average of 10 days after they first felt symptoms. Those who didn’t receive any COVID treatment tested negative after an average of 17 days.
If you stop taking Paxlovid too early, your COVID symptoms may worsen or return. You may also have a higher risk of complications from the illness. Be sure to take Paxlovid as directed for the entire 5-day course (even if you feel better sooner than that).
The bottom line
Paxlovid rebound is a term used to describe when a person experiences worsening of COVID-19 symptoms after initially getting better after taking Paxlovid (nirmatrelvir / ritonavir). But COVID rebound isn’t a side effect of Paxlovid. It can happen to people taking any COVID treatment, as well as to people who received no treatment at all.
COVID rebound tends to happen between 3 to 7 days after a person’s last dose of Paxlovid or other COVID treatments. Current research suggests COVID rebound is mild and lasts roughly a week.
Experts aren’t sure yet who’s at greatest risk for COVID rebound after finishing Paxlovid. Rebound COVID is contagious, so you should isolate yourself if it happens to you. Taking another course of Paxlovid isn’t recommended to treat rebound symptoms. If your symptoms become severe, contact your primary care provider to discuss next steps.
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References
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