But the report, on the experiences of 13 patients, found that the drug had no benefit for some people and that some who benefited said the improvement didn’t last.

A small study published Monday found that the COVID-19 antiviral treatment Paxlovid may have use as a treatment for long COVID when administered outside of an infection. Administration of Paxlovid during a SARS-CoV-2 infection has previously been linked to a lower risk of developing long COVID symptoms.

Extended courses of Paxlovid may alleviate symptoms in some patients with long Covid, though its effectiveness varies widely.

An up-close look at how patients respond to the drug at different times and doses adds nuance to a recent finding that Paxlovid does not work for long COVID.