READ THIS NEXT: Vaccinated People Are “Extraordinarily Vulnerable” to This, New Study Finds. One of the latest concerning COVID trends noted by researchers is the occurrence of rebound infections following one common COVID treatment. Paxlovid—an oral antiviral pill created by Pfizer and designed to be taken at home to prevent severe COVID—has become increasingly popular over the last few months. In the recent weeks, however, more and more people have been reporting that they’ve experienced COVID relapses after taking Paxlovid.ae0fcc31ae342fd3a1346ebb1f342fcb Peter Hotez, MD, the dean of the National School of Tropical Medicine at Baylor Medical College who is both fully vaccinated and boosted, recently tweeted that he had recovered from COVID with two negative tests and felt fine after finishing a five-day course of Paxlovid. But five days later on May 17, he said he woke up to a runny nose, sore throat, and a positive COVID test. “So either this post-Paxlovid relapse is real … or something,” Hotez tweeted. “We’ll eventually figure this out, but still a puzzle. I don’t feel that terrible it’s like a bad cold … will a [second] course of Paxlovid help? Not much of a roadmap.” People infected with COVID and being treated with Paxlovid aren’t the only ones at risk from rebound cases, though. A group of researchers from the Veterans Administration (VA) Medical Center in Boston teamed up with researchers at Columbia University to look into COVID infections that occur after a Paxlovid treatment, CNN reported on May 31. Michael Charness, MD, chief of staff at the VA Medical Center, told the news outlet that they’ve found at least two instances where people have transmitted the virus to someone else after a rebound case. “People who experience rebound are at risk of transmitting to other people, even though they’re outside what people accept as the usual window for being able to transmit,” Charness told CNN. RELATED: For more up-to-date information, sign up for our daily newsletter. In one of the cases, the researchers found that a 67-year-old man infected his 6-month-old grandson with COVID after being around the child for half an hour. According to CNN, the man was 12 days past his first positive COVID test, and he had already taken a five-day course of Paxlovid. When he saw his grandson, the man was reportedly feeling better and did not have any COVID symptoms. But eight hours later, he started feeling sick again and the child, as well as both of his parents, tested positive for the coronavirus three days later despite not having any other close contacts before falling ill. “It indicates that you can transmit during rebound even before you develop symptoms,” Charness told CNN. “And you know, we studied a small number of people. It’s certainly conceivable that there are other people out there who don’t have symptoms and still have a viral rebound.” Due to a notable rise in people experiencing COVID again following a treatment of Paxlovid, the CDC just put out new recommendations. On May 24, the agency released an official health advisory, advising anyone who tests positive for COVID again after taking Paxlovid to isolate for another five days. “If you get better and then you get worse again or if you decide to test and you have a test that’s positive, especially after a negative test result, the recommendation is to re-isolate for at least five more days and continue masking for at least 10 more days,” Lauri Hicks, DO, the chief medical officer for the CDC’s COVID response, told USA Today. According to the CDC, people can end their re-isolation period after five days if their fever has resolved for 24 hours without the use of fever-reducing medications and their symptoms are improving. “The individual should wear a mask for a total of 10 days after rebound symptoms started,” the agency advises. “Some people continue to test positive after day 10 but are considerably less likely to shed infectious virus. Currently, there are no reports of severe disease among persons with COVID-19 rebound.” READ THIS NEXT: Top Virus Expert Warns This Is the “No. 1” Thing Vaccinated People Must Do Now.