COVID Encore: What’s Causing the Paxlovid Rebound?


JACKSONVILLE, Fla. (Ivanhoe Newswire) — It seems like either you’ve had it or know someone who has. And now, there are new omicron variants of COVID that are dominant in the US … raising fears of a new winter surge. The new subvariants called BQ1 and BQ1.1 seem to strike even those who are vaccinated or have had the virus before. If you get it, one drug, Paxlovid, is the drug of choice—but why do so many who take the drug, get COVID again a few weeks later? Ivanhoe reports on COVID and what may be causing the paxlovid rebound

It’s a COVID encore! Last year, Stephen Colbert joined.

President Joe Biden, the first lady Jill Biden, even Doctor Anthony Fauci when their COVID-19 infections returned after they finished taking Paxlovid.

Davey M Smith, MD, Infectious Diseases at UCSD School of Medicine says, “So Paxlovid is an antiviral that specifically works on the virus.”

In clinical trials, Paxlovid was nearly 90 percent effective at preventing hospitalizations and deaths in high-risk patients. However, studies show COVID-19 rebound seems to be more common in people who take Paxlovid.

“We have lots of people who get symptoms that come back.” Explains Doctor Smith.

Doctor Smith is trying to find out why. His team at UC San Diego first thought the virus became resistant to the medication. “We took the virus to the lab, it wasn’t resistant. So, then we thought, well maybe the person didn’t have a good enough immune response. So, we looked at that and it seemed like there was enough neutralizing antibody that was there. So, then we were left with maybe we just didn’t treat the person long enough.”

Researchers are finding that the rebound of COVID-19 symptoms after Paxlovid is likely due to insufficient drug exposure, and that not enough of the drug was getting to infected cells. They believe the drug may need to be given for a longer period of time. Now they’re working on figuring out just how long that is. But until then, Doctor Smith says the prescribed five days of Paxlovid is still a person’s best defense against suffering severe life-threatening symptoms.

Doctor Smith says, “So, don’t be scared of Paxlovid rebound. If you need the medication, take the medication.”

In the future, doctors hope physicians will be able to test whether patients require a longer duration of Paxlovid treatment or if they might be best treated by a combination of drugs.

Contributors to this news report include: Marsha Lewis, Producer; Roque Correa Videographer and Editor.



REPORT #3034

BACKGROUND: COVID rebound happens when a person who has COVID-19 tests negative, then within two to eight days has a recurrence of symptoms or a new positive test. Research, published in JAMA Network Open, determined that COVID-19 recovery is “variable and undulating” and that symptoms often return even after a person has overcome the virus. Before the release of Paxlovid (an antiviral drug regimen for COVID), patients were experiencing COVID rebound. The pattern had become more noticeable after a Paxlovid treatment. A new study by researchers at the U.S. Department of Veterans Affairs found that subjects who took Paxlovid had a 26 percent reduced risk of developing a number of long COVID conditions, including heart disease, blood-clotting issues, fatigue, muscle pain, brain fog, and shortness of breath.


WHAT IS PAXLOVID: Paxlovid is an oral treatment that is recommended for people who are older, immunocompromised, unvaccinated, or have an underlying medical condition. These conditions include diabetes or heart disease that puts them at risk of hospitalization or death from COVID-19. Paxlovid is composed of two separate medications. One is nirmatrelvir, a type of drug called a protease inhibitor that blocks the coronavirus from replicating in the body. The second component, called ritonavir, gives nirmatrelvir a boost by slowing the rate at which it is metabolized by the liver. A typical treatment is over the course of 5 days. Two nirmatrelvir pills and one ritonavir pill are taken together in the morning and then again in the evening, starting within a few days of developing COVID-19 symptoms or testing positive. However, it’s important to know that ritonavir can slow the rate at which the body metabolizes a variety of other medications a person may be taking, which could increase the concentration of those drugs in the blood.


COVID RESEARCH PROMISING: Researchers see promise in mRNA vaccines to treat cancer, cystic fibrosis, and rare, inherited metabolic disorders. Pfizer and Moderna worked on mRNA vaccines for cancer way before they developed COVID shots, and now researchers are conducting dozens of clinical trials of therapeutic mRNA vaccines for pancreatic cancer, colorectal cancer, and melanoma, which frequently responds well to immunotherapy. Dr. Michelle Monje, a professor of neurology at Stanford University, has found similarities in the cognitive side effects caused by COVID and a side effect of cancer therapy often called “chemo brain.” Learning more about the root causes of these memory problems could help scientists eventually find ways to prevent or treat them.


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