In an attempt to reverse persistent or rising coronavirus case counts on campuses, some colleges over the last several weeks have put students on lockdown.
Some of these institutions are allowing students to attend in-person classes, while others have ordered them to stay put except to pick up meals or seek medical care.
Colleges entered the spring term generally more confident in their ability to contain the virus. However, several factors, including students' fatigue in following mitigation measures, makes doing so a challenge.
Institutions that brought students back to campus this fall did so cautiously, often inviting them in waves to curtail the virus's spread, said Chris Marsicano, founding director of the College Crisis Initiative at Davidson College, in North Carolina.
Case numbers still tended to spike, but they generally subsided after a month or so, said Marsicano, whose research group is tracking colleges' responses to the pandemic.
But the pattern didn't hold true for the spring, he said. Instead of falling, case counts stayed flat or surged, in part because some colleges opted to bring students back to campus all at once, Marsicano said.
Now, institutions are cracking down.
The University of San Diego's some 1,000 residential students were told last week to remain home as much as they are able. Its president attributed off-campus gatherings to an upswing in verified cases.
The University of Massachusetts Amherst similarly confined students earlier this month, ordering those on and off campus to stay in their residences except for meals, coronavirus testing and medical appointments. The school threatened disciplinary action for those who didn't follow the directive.
More recently, the University of Virginia prohibited in-person gatherings and asked students living on and off campus to remain home. The institution cited a "troubling" increase in case numbers and said it detected one of the more contagious variants of the virus, its student newspaper reported. New strains have been reported on multiple campuses.
While many colleges have beefed up testing this spring, some are using antigen testing, Marsicano said, which can yield rapid results but may turn up more false negatives than other testing types, according to the U.S. Food and Drug Administration.
"Students who get tested feel this false sense of security and socialize, but are spreading the virus," he said.
Campus shutdowns, coupled with robust testing, makes sense, because the virus seems to be transmitted at events where students are flouting health rules, said A. David Paltiel, a public health professor at Yale University. Administrators are more to blame than students, he said, as it's not feasible to expect young adults to abide by these mandates.
Marsicano predicted the lockdowns were in some cases a precursor for shuttering campuses entirely, a trend that played out in the fall. Colleges may be wary of sending students home immediately as doing so would likely exacerbate the spread of the virus as they travel.
"These pauses seem to be the best tool we've got," he said.