As the Thanksgiving holiday looms, more colleges and universities in the United States continue to abruptly shut down their campuses for the remainder of the fall semester because of increased COVID-19 cases across the country.

At the beginning of the COVID-19 shutdown last spring, colleges and universities scrambled to respond to the pandemic and keep students safe. A George Mason University (GMU) study found that three-quarters of 575 colleges with more than 5,000 students had moved courses online, discouraged campus housing, canceled travel, closed campuses, and worked remotely.

That study, published October 16, analyzed actions colleges had made between February 25 and March 31.

"Spring break was this wonderful opportunity that just happened to be occurring at the right time that gave universities the bandwidth to be able to transition relatively smoothly for the spring," said Michael von Fricken, an assistant professor at GMU who worked on the study published in Plos One.

"We've reached this point where universities are only able to be shut down for so long," said von Fricken. "It's becoming more and more about balancing finances and student safety."

Universities have had to adjust again for the fall semester and rising numbers of COVID-19 cases.

In the past few weeks, many universities have quickly suspended in-person classes because of the surge. Brown University in Rhode Island, Northern Michigan University, the University of Maryland, and Syracuse University in New York are among 41 schools that most recently have suspended in-person instruction.

"In recent weeks, we have seen an increase in positive tests among students, faculty and staff," wrote Brown University President Christina H. Paxson in a letter to students on November 17.

"Although infection rates at Brown are still quite low, and we have ample space for quarantine and isolation, these increases are nevertheless concerning," Paxson wrote.

Since the pandemic began, there have been more than 321,000 COVID-19 cases on college campuses and at least 80 deaths, according to New York Times data from more than 1,900 U.S. colleges and universities.

"What's been happening in this fall, and what's going to happen in the spring, is universities are getting a feel for, 'Are they able to have a safe return to campus?'" asked von Fricken. "They're going to look at the schools that have been successful and try and emulate those programs."

The University of Pennsylvania, the University of Arizona, the University of California in Los Angeles and Berkeley, Syracuse University and the University of Michigan are among schools ending all in-person classes for the semester after Thanksgiving.