U.S. Seeks ‘Urgent’ Data on Covid Relapses After Using Pfizer’s Drug

U.S. government researchers are planning studies of how often and why coronavirus levels rebound in some Covid patients who have completed a five-day course of treatment with Pfizer Inc.’s Paxlovid. 

“It is a priority,” said Clifford Lane, deputy director for clinical research at the National Institute of Allergy and Infectious Diseases, calling the issue “a pretty urgent thing for us to get a handle on.” The agency is discussing a variety of possible epidemiological and clinical studies to examine post-Paxlovid rebound with scientists at the Centers for Disease Control and Prevention, he said.

The demand for answers is rising as Paxlovid has become a key element of the Biden administration’s pandemic approach, with the drug being made available at pharmacies nationwide. Among other questions the NIH hopes to get a better handle on is how often viral rebounds occur after five days of Paxlovid treatment, who’s at risk for relapse, and whether it could be avoided with a longer regimen.