As positive Covid case counts grow on campuses, some of which have detected evidence of the more contagious Omicron variant, a small number of colleges have decided to move their final days of the fall semester online and cancel in-person activities.

Following Cornell University’s announcement Tuesday morning that finals would be administered remotely for the rest of the week and a ceremony for December graduates would be canceled, Princeton, New York, and George Washington Universities and the University of Pennsylvania announced similar plans. Princeton said Tuesday that all finals would be taken online and mandated the Covid-19 booster shot for all students, faculty members, and staff who return for the spring semester, The Daily Princetonian reported. NYU said they “strongly encourage fall exams to be given online and canceled “non-essential, non-academic gatherings.” GWU canceled in-person gatherings and, beginning Friday, moved exams online, The GW Hatchet reported. The University of Pennsylvania said that exams scheduled for the week of December 20 would be online as a precautionary measure, The Daily Pennsylvanian reported.

“This is not quite how we expected to end the semester; however, if there is any consistency to the coronavirus, it is its unpredictability,” NYU’s announcement said.

Those universities cited raising case numbers and, in some cases, evidence of the Omicron variant. Cornell said that its Covid-19 testing-lab team identified evidence of the variant in a significant number of cases, but that those results were still preliminary. GWU said its public-health team had also discovered the variant in a small number of cases.

At these universities, the vast majority of students are vaccinated. At Princeton and NYU, 99 percent of undergraduate students are vaccinated, while at Cornell 97 percent of the on-campus population are vaccinated. Cornell’s statement said that the university had not seen cases of severe illness in this surge.