In about a third of individuals with Covid, whether they’ve been treated with Paxlovid or not, symptoms rebound, according to a study published online Tuesday.
The preprint study — which hasn’t yet been published — found that after initially improving, 27% of people with Covid suffered a rebound in their symptoms.
“It happens all the time. People who go untreated for Covid and then feel better will often get symptoms afterwards, said study co-author Dr. Davey Smith, an infectious disease specialist and global public health scientist at the University of California, San Diego School of Medicine. And not only that, but the 27% finding was higher than what he’d expected based on anecdotal evidence.
And this is documented in people who have taken Paxlovid, and it’s referred to as Paxlovid rebound, and a study found that the viral rebound occurred regardless of whether a person took the antiviral treatment.
Anyone who has had Covid could see their symptoms return within a few days, and they might be even worse or not as bad as the first time, Smith said. It’s just the natural course of the infection.
When the agency in May issued a health alert informing physicians about Paxlovid rebounds, it also said that some people with SARS-CoV-2 (the virus that causes Covid-19) infection may experience a brief return of symptoms independent of treatment with Paxlovid and regardless of vaccination status.
Paxlovid rebounds, in particular, have received a lot of attention in recent weeks, with both President Joe Biden and his chief medical advisor Dr. Anthony Fauci testing positive days after consuming the antiviral.
The company’s clinical trial for the drug found that 1% to 2% of people who took Paxlovid tested positive for the coronavirus after testing negative. The drug manufacturer stated in a fact sheet for physicians that this also occurred at similar rates among the placebo group.
It’s still hard to determine if a rebound is directly caused by Paxlovid, even if they’ve taken the drug.
Smith agreed: You have symptoms that change over time, and you have a viral antigen that changes over time, and it goes up and down with or without Paxlovid.
Paxlovid is doing its job: protecting us from life-threatening infections, Ko said. “These rebounds are happening, but they’re preventing the serious consequences.”