‘They’re not ready’: Students are about to flood college campuses. The virus could, too.

Hundreds of the nation’s colleges and universities plan to bring thousands of students back to campus next semester even though most of the schools are unprepared or unequipped for the volume of testing needed to keep Covid-19 infections in check.

The lack of robust campus testing plans comes despite growing scientific consensus that colleges should include frequent Covid-19 scans to help stop and prevent outbreaks. And a vaccine will not eliminate the need to test students, an expert panel said last week.

A promising testing method Duke University fine-tuned this fall is one example schools can follow this spring — scanning miniature pools of mixed student samples to quickly look for signs of disease.

But experts warn the effort took extensive planning, major campus buy-in, money and help from relatively low community infection rates. Without that kind of surveillance, colleges risk becoming hot spots where the virus races through dorms, parties and surrounding areas.

“They’re not ready, by and large,” said Chris Marsicano, director of the College Crisis Initiative at Davidson College.

Early projections from Marsicano’s team say about 60 percent of U.S. higher education institutions plan to host classes with all or some portion of their students on campus in 2021. Only an estimated 8 percent of them are prepared to test each of their students at least once a week.

“Can campuses open successfully in the spring without robust testing? The answer is, yes they can,” Marsicano said. “Should they? Absolutely not.”

Princeton University set up an on-campus testing laboratory, concluding that a combination of regular testing and rigorous adherence to mask-wearing and social distancing will allow thousands of undergraduates to return to New Jersey for the spring semester. Harvard University plans to bring back seniors and juniors who completed the fall semester as well as students who live four or more hours from the Eastern Standard Time zone and those who need to be on campus for coursework. Other schools, many of them smaller liberal arts colleges with significant endowments, are pressing ahead with similar protocols first tested this fall.

Even the University of North Carolina at Chapel Hill, which retreated from its in-person teaching plans in August after off-campus parties caused infection rates in their communities to spike, has plans to bring back some students in person. The university said it “learned important lessons from our experiences and those of our peer universities,” and will allow “students to live and learn on campus,” with some modifications. Faculty already are pushing back against the proposal, saying the university’s spring plans “are doomed to repeat too many of the failures of the fall.”

One driving factor behind the push to reopen may be the avalanche of lawsuits that followed last spring’s shift to online courses. More than 150 suits from students and parents around the country demanded refunds for tuition and fees. Students and parents questioned whether an online education was worth the same price as a traditional college experience.

Colleges inviting students back justify it for other reasons, however. Harvard explained how “vital the junior year is” to help their students complete capstone projects to graduate, and the difficulties students who lived in different time zones faced in accessing classes. UNC Chancellor Kevin M. Guskiewicz also acknowledged that “there is still a great deal of uncertainty,” but promised to closely monitor the situation. UNC “will be ready to alter our plans and make necessary accommodations,” he said, adding that changes to the semester will be announced by Jan. 9.

Campus Covid-19 testing will still be necessary even after a vaccine becomes available, a group of experts said in a research briefing out this month from the National Academies of Sciences, Engineering, and Medicine. It will take time to distribute doses, the panel said, and college students will not be a high-priority population for the initial round of shots.

Testing alone is not a solution, either. Schools that reported early success in containing the virus this fall often had low infection rates in surrounding communities, plus multimillion-dollar pandemic management strategies that stressed mask-wearing, social distancing and isolating the infected, as well as broad, mandatory testing.

“Very few institutions are able to do that,” Marsicano said. “The reason is, it’s really, really expensive.”

Duke designed its own method to fast-track coronavirus checks by scanning a cocktail of nasal swab samples without straining testing resources. The effort, based on a tactic pioneered during the HIV crisis, caught an infection cluster at an off-campus apartment early and might have prevented outbreaks in the surrounding area.

One big catch: Experts warn Duke’s “pooled testing” strategy is most effective when overall infection rates are lower.

“The numbers start to work against you as your incidence rate starts to rise,” said Tony Moody, a Duke infectious disease expert and laboratory director of the university’s Human Vaccine Institute, during a recent call with reporters.

While new, cheap and rapid testing technologies are coming onto the market, schools often continue to rely on so-called PCR tests that are more sensitive but prone to supply shortages and processing backlogs. Pooled testing can help ease the strain on those limited resources.

Duke regularly tested broad swaths of students for the virus, whether they had symptoms or not, and combined portions of five test specimens into a single tube destined for an in-house, lab-developed test. If one of those combined samples spotted a potential infection, each of the underlying individual specimens was flagged for follow-up testing through a process known as “deconvolution.”

Duke concluded the entire process could be completed in 18 to 30 hours and saved on chemical testing reagents and laboratory resources that would have been used if each individual specimen were tested immediately.

Among more than 10,000 Duke students who were tested nearly 69,000 times between early August and mid-October, school researchers said 84 students tested positive, half of whom were asymptomatic. That suggests a “substantial proportion of infections” would be missed if schools test only patients who show Covid-19 symptoms, researchers recounted in a recent CDC report.

Colleges hoping to follow Duke’s example should take note that labs can expect to retest higher numbers of individual samples out of infected pools as surrounding community infection rates grow. That could slow down the process and still tax resources.

“If you are pooling, and you have an incidence rate that’s high enough that a majority of your pools are turning positive, that means you’re doing more tests on deconvolution than you might if you were just directly testing students,” said Steve Haase, a Duke biology and medical professor, during a recent call with reporters.

That has been part of Duke’s edge, Moody added.

“We’ve been lucky enough to have a relatively low infection rate, and so our pooling strategy has really worked in our advantage,” Moody said. “We’re using fewer clinical tests by doing this, rather than sending a lot of samples to the clinical lab, which I think has been an advantage.”

Vague guidelines, difficult logistics and steep costs still present immense hurdles for schools with weak or incomplete testing plans. Marsicano said that means federal and state officials need to shell out more funding for schools to carry out major testing efforts, especially at state institutions that housed major outbreaks in the fall semester.

“At the very least, every institution needs to be testing every student when they walk in the door,” he said. “Because if they can test students when they arrive on campus, and they can keep students from leaving the campus community, then you can figure out who has it, isolate those people and you’ll have fewer cases because you stamped it out in your community.”

All UNC institutions say they plan to conduct reentry testing for the spring semester or require students to show a negative Covid-19 test before coming back to campus. Students will undergo follow-up testing twice a week throughout the semester, and the university’s health center recommends students get tested every five to nine days. North Carolina State University also will test everyone when they return.

While faculty noted that “UNC’s testing plans for spring are vastly improved,” they still urged university officials to cancel face-to-face instruction plans.

“We have every reason to expect that the University will — once again — be overwhelmed by infections when classes resume,” they wrote. “Are Chapel Hill’s leaders ready to face that reality when it comes?”

Some colleges are sticking with remote classes for another term. All 23 California State University campuses, which enroll a combined 482,000 students, largely will continue teaching classes virtually, CSU Chancellor Timothy P. White said in an early September decision.

“This decision is the only responsible one available to us at this time,” White said. “Testing infrastructure is still a work in progress in California and at the CSU, and testing remains very expensive to conduct repeatedly and meaningfully with rapid results — both of which are necessary to mitigate the spread of Covid-19.”