Authors: MATTHEW PERRONE May 9, 2022 AP NEWS<\/p>\n\n\n\n
As more doctors prescribe Pfizer\u2019s powerful COVID-19 pill, new questions are emerging about its performance, including why a small number of patients appear to relapse after taking the drug.<\/p>\n\n\n\n
Paxlovid has become the go-to option against COVID-19 because of its at-home convenience and impressive results in heading off severe disease. The U.S. government has spent more than $10 billion to purchase enough pills to treat 20 million people.<\/a><\/p>\n\n\n\n But experts say there is still much to be learned about the drug, which was authorized in December<\/a> for adults at high risk of severe COVID-19 based on a study in which 1,000 adults received the medication.<\/p>\n\n\n\n WHY DO SOME PATIENTS SEEM TO RELAPSE?<\/p>\n\n\n\n Doctors have started reporting rare cases of patients whose symptoms return several days after completing Paxlovid\u2019s five-day regimen of pills. That\u2019s prompted questions about whether those patients are still contagious and should receive a second course of Paxlovid.<\/p>\n\n\n\n Last week, the Food and Drug Administration weighed in. It advised against a second round because there\u2019s little risk of severe disease or hospitalization among patients who relapse.<\/p>\n\n\n\n Dr. Michael Charness\u00a0reported\u00a0<\/a>last month on a 71-year-old vaccinated patient who saw his symptoms subside but then return, along with a spike in virus levels nine days into his illness.<\/p>\n\n\n\n Charness says Paxlovid remains a highly effective drug, but he wonders if it might be less potent against the current omicron variant. The $500 drug treatment was tested and OK\u2019d based on its performance against the delta version of the coronavirus.<\/p>\n\n\n\n \u201cThe ability to clear the virus after it\u2019s suppressed may be different from omicron to delta, especially for vaccinated people,\u201d said Charness, who works for Boston\u2019s VA health system.<\/p>\n\n\n\n Could some people just be susceptible to a relapse? Both the FDA and Pfizer point out that 1% to 2% of people in Pfizer\u2019s original study saw their virus levels rebound after 10 days. The rate was about the same among people taking the drug or dummy pills, \u201cso it is unclear at this point that this is related to drug treatment,\u201d the FDA stated<\/a>.<\/p>\n\n\n\n Some experts point to another possibility: The Paxlovid dose isn\u2019t strong enough to fully suppress the virus. Andy Pekosz of Johns Hopkins University worries that could spur mutations that are resistant to the drug.<\/p>\n\n\n\n \u201cWe should really make sure we\u2019re dosing Paxlovid appropriately because I would hate to lose it right now,\u201d said Pekosz, a virologist. \u201cThis is one of the essential tools we have to help us turn the corner on the pandemic.\u201d<\/p>\n\n\n\n HOW WELL DOES PAXLOVID WORK IN VACCINATED PEOPLE?<\/p>\n\n\n\n