Influenza outbreaks have always been of particular concern on college campuses, where close-quarters living, crowded lecture halls and fluid social circles make airborne transmission especially easy. But the past two flu seasons were almost nonexistent on campuses, thanks to remote learning during the COVID-19 pandemic—which kept them empty—or masking and social distancing policies when students returned.

This winter, as colleges and universities cast off two years of caution, the flu is returning to campuses early and spreading fast.

The problem goes beyond densely populated campuses. While flu season usually peaks in late December or January, this year’s strain swept across the country last month, and infections are already at levels not usually reached until January or February, according to the latest CDC data. This year’s strain also appears to be more severe: more than 78,000 people have been hospitalized with flu since Oct. 1, 40 times more than at this same time last year, according to the CDC. Between the rapid spread and increased severity, some experts are saying this winter may see the worst flu outbreak in over a decade.

At the University of Pittsburgh, flu is overtaking COVID as the airborne virus of greatest concern. In a Nov. 8 message to the university community, Pitt’s COVID-19 Medical Response Office said there are likely to be “many more cases of flu than cases of COVID-19” at the end of the semester—and that those cases could be more severe than normal.

A Pitt spokesperson did not provide case numbers for this fall but said students were asked to be vigilant and proactive in protecting against infection.

“We encourage all students to take steps to stay well, like getting flu shots and COVID-19 boosters now and practicing good hand hygiene,” the spokesperson wrote in an email to Inside Higher Ed. “There is no one-size-fits-all treatment for the flu … prevention is the best strategy.”

‘A Perfect Storm’

Dr. Richard Zimmerman, the principal investigator for the Pittsburgh location of the CDC’s U.S. Influenza Vaccine Effectiveness Network, blames the abnormally bad flu season largely on the population’s lowered immunity to respiratory viruses, which degraded over two years of masking and social distancing. While pandemic restrictions like those put in place on college campuses protected people from COVID, he said, it ultimately made them more vulnerable to a host of other airborne respiratory illnesses.

That lower immunity, coupled with the easing of public health measures to prevent COVID’s spread, has created the “perfect storm” for a bad campus flu season.

“There has been limited flu circulation during the pandemic thanks to social distancing and masking measures for the past two years,” said Dr. Zimmerman, who is also a professor of family medicine at Pitt. “As the immunity has worn off, more people are susceptible, and social distancing and masking have relaxed at the same time.”

Dr. Zimmerman said the same principle applies to any airborne respiratory virus, including respiratory syncytial virus, or RSV, which has also been spreading on college campuses this fall. In most patients, RSV largely mimics mild cold symptoms, but it can be dangerous or even fatal to young children, seniors and the immunocompromised.

The Pitt spokesperson said the university’s health services center is able to test for RSV as well as flu and COVID and that they have antiviral medication on hand if necessary.

Between the early flu season, RSV and the ever-present threat of another COVID variant sweeping across campuses, student health centers are bracing themselves for a potential “tripledemic.” Some, like Indiana University, saw an abnormally high number of sick students after Thanksgiving break—and not just with flu, RSV or COVID.

“There are many other upper respiratory illnesses circulating besides these three, so there are a lot of people that are sick right now,” Dr. Beth Rupp, medical director of IU’s Student Health Center, told the Indiana Daily Student.

Anita Barkin, co-chair of the American College Health Association’s COVID-19 Task Force, said students did seem to be getting sick at higher rates this fall, and that the adjustment to post-pandemic campus life will likely involve higher infection rates for a variety of viruses.

“[COVID] took the focus off colds and flus, but we weren’t getting colds and flus anyway, because we were using all these public health strategies for COVID,” she said. “Once those fell away, it increased the risk for other viruses, not just flu. So we’ve got to adjust our focus.”

Repurposing COVID Safety Measures

There was an alarming spike in flu cases on campuses early in fall 2021, but the Omicron variant of COVID resurrected many precautions just a few weeks later, stanching the flu’s spread. Barkin said that encouraging a return to some of those practices, including widespread indoor masking and diligent hand washing or sanitizing, would go a long way toward limiting the spread of flu on campus.

“The mitigation strategies on campuses during COVID led to an almost nonexistent flu season the past two years, so we know the strategies that worked in preventing the spread of COVID also work to prevent the spread of the flu,” she said. “All the messaging and lessons that colleges learned from the pandemic are totally in sync with flu prevention, as well as RSV and the common cold. Institutions should draw from that experience.”

Barkin acknowledged, however, that the likelihood of returning to strict COVID protocols is low.

“There’s little appetite to return to masking and social distancing policies,” she said. “The focus right now should be on stressing vaccine confidence and getting students their flu shots.”

Dr. Zimmerman said that even in the absence of campuswide safety measures, students can—and maybe should—take matters into their own hands to reduce their exposure by choosing to mask in lecture halls and gyms or by refraining from large social gatherings when possible.

“We can’t stay in lockdown forever, but there are times when individuals will want to use protective measures for their family or for their own personal schedules,” he said. “This might be one of those times.”