For some people, including US President Joe Biden and National Institute of Allergy and Infectious Diseases Director Anthony Fauci, relief from the disappearance of COVID-19 symptoms and a negative test was fleeting. Biden, Fauci and many others have seen their tests come back positive or have unwanted symptoms recur after following a five-day course of the Paxlovid antiviral. Other people have experienced a resurgence of infections even without taking the drug.
Several studies have described cases of “Paxlovid rebound” after treatment. In one, seven patients treated with Paxlovid experienced a rebound of the virus to high levels after the end of treatment and symptoms returned for six of them, virologist Jonathan Li and colleagues reported in June in Clinical Infectious Diseases.
Samples from three patients even carried an infectious virus, a clue that some people who experienced a rebound might infect others. Another study that has yet to be peer-reviewed by other researchers found that fewer than 6 percent of people in the study who were prescribed Paxlovid he had rebound infections in the following month at the end of the treatment.
It’s unclear why the Paxlovid rebound occurs, says Li, of Brigham and Women’s Hospital and Harvard Medical School. Studies show that people who have been given the drug still develop a strong immune response to the virus after five days of treatment.
“I think what’s happening in that situation is that the replication of the virus has been inhibited. Suddenly, the drug is gone and the virus has a momentary opportunity to replicate. And it replicates at high levels “, Li says. But by then, the immune system learned to fend off the coronavirus. If newly trained immune cells encounter newly produced viruses and set off alarm bells, symptoms may briefly recur.
Covid-19 and distrust in drug therapies
Some people may not want to take the drug because they are worried about the rebound, Li says. But Paxlovid himself is probably not the cause. The drug is not failing. It is still highly effective in preventing serious diseases. “I would not hesitate to give Paxlovid to my patients”Li says. “I tell them to pay close attention to looking for rebound symptoms. But it doesn’t dissuade me in terms of statute of limitations ”.
Fauci took another route from Paxlovid in the wake of his rebound. The U.S. Food and Drug Administration says there is no evidence that 10 days of treatment is more effective than five days or that patients need to repeat. But researchers are testing whether taking the drug for a longer period of time could prevent rebound.
The rebound of COVID-19 is not limited to patients taking Paxlovid. He reminds them that even in the early days of the pandemic, some patients came to him in the hospital saying they had started to feel better but they quickly got worse again. It’s hard to know how to interpret such anecdotal reports, he says. Researchers are still learning what an untreated viral infection can look like in the body.
Although the brief invasion of the virus (hopefully) may seem simple on average, with virus levels in the body rising to a peak before slowly decreasing as the person recovers, not everyone follows this pattern.
“My husband had COVID-19 two months ago. His symptoms lasted for about a week and he was happy to see the line on his antigen test get fainter. Even so, despite him feeling perfectly healthy, the line suddenly returned to full strength almost immediately after adding his sample to a new test days later. He was frustrated and, as a social person, he complained about having to remain isolated. “
Studies show he’s not alone. When Li and colleagues studied disease course in COVID-19 clinical trial participants who received placebo treatment, 1 in 8 people had a rebound, with symptoms recurring for 1 in 4 people.
That rebound, however, typically lasted about a day and few had both elevated viral loads and returning symptomsthe team reports in a preliminary study published Aug.2 on medRxiv.org which has not yet been peer-reviewed by other scientists.
In this case, there is no drug with disappearing effects. Any symptoms returning without a positive test could be due to something else like allergies or a different respiratory virus, Li says. It is also possible that the virus is replicating in different parts of the body at different times. Some tests may be negative when the body clears the virus from the throat, for example, but it is still replicating at low levels in the nose.
“This latter scenario could have happened with my husband. In a confusing twist, he tested negative on two saliva PCR tests while continuing to test positive on nasal antigen tests. A PCR test is much more sensitive, so we expected the opposite to happen. Since experts say they take a positive antigen test as a sign that you are still contagious, he remained isolated until he tested negative on an antigen test two weeks after his first symptoms appeared. “
“Fortunately, he has now fully recovered and is not at all keen to repeat the experience. This means that we are still masquerading in public spaces and taking other precautions. We know we’re not done with this pandemic “. Bring back a patient’s wife
#Covid19 #rebound #phenomena #subjects