After being treated with the antiviral drug Paxlovid, US president Joe Biden repeatedly tested negative for four days. Despite showing no symptoms, he tested positive on Saturday in what is known as Paxlovid rebound, a phenomenon in which patients treated with the drug have shown symptoms
Several patients who were treated with Pfizer’s Paxlovid medication tested positive after being cured of COVID-19. AFP
United States President Joe Biden has gone back to isolation after testing positive for COVID-19 for the second time on 30 July. He was repeatedly tested negative earlier in the week. The White House doctor has attributed the test result to “rebound” positivity from treatment he had received.
The US President’s reinfection is another example of “Paxlovid rebound” – a phenomenon witnessed among patients who were administered the famous antiviral drug Paxlovid.
Before Biden, Dr Anthony Fauci, chief medical officer to the President, experienced a Paxlovid rebound as well.
According to The Atlantic, more than a third of Americans who have tested positive for COVID-19 this summer were treated with Paxlovid, and a large number of these tested back positive soon after testing negative.
What is Paxlovid?
An oral antiviral, developed by Pfizer, Paxlovid has proved to cut the risk of hospitalisation and death by 89 per cent, according to The Atlantic. It was termed “a real game changer” by US President Joe Biden in January this year.
As per Patrick Jackson, assistant professor of Infectious Diseases, University of Virginia, Paxlovid is made up of two protease inhibitors, including one used in treating HIV as a booster medicine.
Protease inhibitors are synthetic drugs that block enzymes that viruses need to replicate. The combination in Paxlovid basically prevents the coronavirus from completing its life cycle, he said in a report for The Conversation.
The US agencies and government have been enthusiastic about the prescription and use of the antiviral drug with more than 40,000 prescriptions being handed out a day.
More than three million courses of Paxlovid have been administered in the United States since December, according to data from the Department of Health and Human Services.
Explained: The controversy around Paxlovid treatment for COVID-19 and ‘rebound illness’
What is Paxlovid rebound?
Over the last few months,the US government has urged medical practitioners to prescribe the Pfizer drug. However, patients in increasing numbers complained of a bitter, metallic taste, or one like grapefruit juice mixed with soap, as reported by The Atlantic.
Some had more serious side-effects as they reported experiencing a second round of symptoms. And when the pills were over they went back to testing positive, a phenomenon that’s become known as “Paxlovid rebound”.
According to a report by Time, Pfizer reported that one to two per cent of people taking the medication experienced rebound.
The company says the rates of rebound in the treated group in its study and among those receiving placebo were similar, indicating that “elevated nasal viral RNA is uncommon and not uniquely associated with treatment.”
The CDC defined rebound cases as “characterized by a recurrence of covid-19 symptoms or a new positive viral test after having tested negative.”
After concern over the phenomenon, the agency issued an advisory in May, recommending that people who experience a resurgence of COVID-19 following treatment should again isolate for five days and wear a mask for 10 days.
Should we be concerned about rebound cases?
Catherine Bennett, a professor of epidemiology at Deakin University in Australia, said in a report by The Washington Post that people should not be concerned by rebound cases, but rather be aware that such cases are possible, and that people should monitor themselves closely after they finish a course of Paxlovid.
In the Indian context, there are a few physicians who have prescribed Paxlovid. The drug does have approval in India. According to The Indian Express, there has been no push from the government for the use of the medication so far.
The CDC said in its advisory that case reports suggest that recurrence results in mild symptoms, and there have been no reports of severe disease so far.With inputs from agencies
Read all the Latest News, Trending News, Cricket News, Bollywood News,India News and Entertainment News here. Follow us on Facebook, Twitter and Instagram.