Georgetown University, like hundreds of other colleges across the country, has revised its grading this semester. (Kevin Lamarque/Reuters)

Niko Savas was trying his best to concentrate on his online classes at Georgetown Law, despite the exhaustion, fever and aches caused by his bout with covid-19.

But the physical sickness wasn’t the coronavirus’s only toll, he said. He worried for his parents, who also have covid-19, he said, and about the possibility that he unwittingly infected others before he knew he was sick.