Pfizer’s blockbuster Paxlovid anti-viral that lowers rates of illness and death in people infected with the coronavirus also cuts the risk of some symptoms of disabling long COVID, a study has found.

Taking the oral medication within five days of testing positive for a SARS-CoV-2 infection was linked to a 26% lower risk of lingering post-viral complications, researchers with the Veterans Affairs St. Louis Health Care System said in the study. That equates to 2.3 fewer cases of long COVID within three months of infection for every 100 patients treated, according to the findings released Saturday on the medRxiv server ahead of publication in a peer-reviewed journal.

The research, based on an analysis of electronic health records in databases maintained by the Department of Veterans Affairs, is the first study to look at Paxlovid’s longer-term effects, said Eric Topol, founder of the Scripps Research Translational Institute in La Jolla, California. It suggests that wider use of the treatment won’t just stave off critical disease during the acute phase of infection, but will limit patients’ likelihood of longer-term problems.