Biden started taking Paxlovid, an antiviral drug

The antiviral pill that President Biden started taking after testing positive for coronavirus has been shown to protect high-risk people from progressing to more severe cases of Covid-19.

Researchers, however, are still working to answer key questions about the drug, including its effectiveness in vaccinated people and whether cases of “rebound” in people who receive it are common.

A study by the Centers for Disease Control and Prevention published last month, incorporating data from a large healthcare system in California, found that of more than 5,000 people who were prescribed Paxlovid for mild to moderate cases of Covid – many of whom were vaccinated – less than 1% needed Paxlovid. hospital or emergency care. According to the study, only six Covid-related hospitalizations and 39 emergency room visits occurred within five to 15 days of using the drug.

There were significant limitations to the study, the researchers warned, including the lack of a control group that did not receive the treatment, making it harder to determine its true benefit or compare it with the benefit of receiving a coronavirus vaccine.

Drugs, authorized in December for high-risk infected people aged 12 and over, has been shown in clinical trials to reduce the risk of hospitalization or death by 88 percent when given to adults within five days of the onset of their symptoms. These data were collected from unvaccinated people when the Delta variant of the virus was in high circulation.

The treatment is supposed to be taken as 30 tablets over five days. Before starting, patients are advised to consult a health care provider about possible drug interactions. Dr. Ashish K. Jha, the White House coronavirus coordinator, said Thursday during a White House press briefing that Mr. Biden had been asked to suspend two medications he is taking, a drug for the cholesterol and a blood thinner, so as not to risk a serious side. Paxlovid effects.

Scientists also worked to understand whether Paxlovid can lead to a recurrence of symptoms or positive tests, a pattern known as rebound. Dr Jha said on Thursday that data from major health systems showed such an outcome was rare, with the percentage of Paxlovid recipients rebounding “in single digits”.

“When people have bounced back, they don’t end up in the hospital. They don’t end up particularly sick,” Dr. Jha said. “Paxlovid works really well to prevent serious disease, rebound or no rebound, and that’s why he was offered it. And that’s why the president took it.

Among the victims of the rebound was Dr. Anthony S. Fauci, Mr. Biden’s chief medical adviser, who suffered of a second bout of symptoms and another positive test last month after several days of testing negative after a series of treatments.

The CDC has released a emergency health notice in May who said people experiencing a rebound “should restart isolation and self-isolate again” for at least five days, reflecting the agency’s general isolation recommendations for people infected with the virus.

He also said that based on some reports, the rebound did not represent reinfection with the coronavirus or the development of resistance to Paxlovid.

Rebecca Robin contributed.