‘Paxlovid rebound’ raises questions over how long antiviral COVID treatment should last

President Biden testing positive for COVID-19 again days after completing a course of Paxlovid has raised the question of whether the length of the antiviral treatment should be reconsidered.

Just days after he completed a five-day round of Pfizer’s COVID-19 antiviral treatment, Biden’s physician, Kevin O’Connor, said in a letter on Saturday that the president had tested positive once again. As of Wednesday, Biden is still testing positive for COVID-19.

This phenomenon has come to be known as “Paxlovid rebound,” when a person tests positive for the coronavirus again even after initially testing negative following a round of treatment with the antiviral.