Sbrana, plagued by fatigue and brain fog since being diagnosed with mononucleosis six years earlier, was convinced that the pernicious new virus would wreak similar havoc in some of those who contracted it.

Her intuition proved prescient. Some people who had suffered even mild cases of covid-19 began complaining of problems that Sbrana knew too well, including muscle pain and drop-dead exhaustion. Now, as millions of people nationwide are suffering from long-haul covid, Sbrana and an army of patient advocates are cautiously hopeful that new research may unlock clues to other conditions that appear to crop up after infections, including myalgic encephalomyelitis/chronic fatigue syndrome, known as ME/CFS.

"I think there is potential," said Sbrana, who suffers from ME/CFS.