Amid a wave of COVID-19 cases driven by the omicron variant, dozens of colleges are making plans to move classes online for at least the first week of the semester.

Harvard University is moving classes online for the first three weeks of the new year. The University of Chicago is delaying its new term and holding the first two weeks online.

Others like Michigan State are inviting students back to campus but starting classes online. Many colleges hope an extra week or two will get them past the peak of a surge. But some say it’s possible the online shift could last longer than expected.