$吉利德科学(GILD)$ 抗病毒药物要用在病毒感染初期，后期效果可能不明显Libby Hohmann, associate professor of medicine and infectious diseases at Massachusetts General Hospital, is similarly cautious. “It’s going to be a challenge to review the data because the protocol allows a wide range of illness into it,” says Hohmann, who leads the hospital’s participation in NIAID’s remdesivir trial. “Unless it’s sort of a home run, it may be difficult to parse at the get go.”One issue is that the first studies to read out are the ones focused on the most severe cases, people whose disease might have progressed past the point of help by an antiviral.

“Everything we do in infectious disease is better treated when it’s early on and the bacterial or viral burden and the damage done is lesser,” Hohmann says. Doctors are realizing that COVID-19 is a two-phase illness, she says, that starts with upper respiratory symptoms that worsen after a week to two weeks. At some point during that period, patients “fall of a cliff,” Hohmann notes. “There’s a lot of data and speculation that it’s a kind of immunological phenomenon,” where certain people’s immune or inflammatory response goes awary.

So if those first data in severe or even moderate cases are unclear, it doesn’t necessarily mean the drug doesn’t work. Rather, it could just mean it isn’t being given early enough.