COVID Testing on Campus Is About More Than the Students

Many U.S. institutions of higher learning, including Duke University where we work, have implemented large-scale COVID-19 testing programs for students, staff, and faculty. In these mass testing programs, everyone is regularly screened — typically weekly or twice weekly using SARS-CoV-2 PCR tests involving nasal or throat swabs. Adherence has been high and students have been supportive, since testing allows for a more “normal” campus experience. Such screening is a critical tool for preventing campus outbreaks.

Why is it so important to avert campus infections? First, while it is true that students are less likely to die from COVID-19 than older adults, there have been hospitalizations and deaths among students, and long COVID can develop at any age. Second, infected students can go on to infect older, more vulnerable adults on campus, including maintenance and service staff and those who are immunocompromised. Around 40% of maintenance staff on U.S. university campuses are people of color, who are at higher risk of dying if they become infected with SARS-CoV-2. Universities that are also healthcare systems have an additional duty to prevent students and staff from infecting patients. Third, campuses are not hermetically sealed off from their host cities; there is strong evidence that campus outbreaks can drive infections into the surrounding community.

Beyond the Why of Preventing Infections, Do We Know the How?

Luckily, almost 2 years into the pandemic, we now know how to avert campus outbreaks. A comprehensive integrated approach to reducing SARS-CoV-2 transmission stands the best chance of success. Before vaccines were licensed, the key elements were:

• (i) using a range of non-pharmaceutical measures, including universal indoor masking, cleaning indoor air with ventilation and filtration, and spacing people out (including by reducing campus density)
• (ii) offering students safer alternatives to unmasked, indoor fraternity parties (e.g. organizing outdoor social events)
• (iii) a robust system of testing, isolating cases, and tracing and quarantining those exposed

Support must be provided to those who are in isolation or quarantine. One modeling study found that the optimal screening strategy, assuming typical behavior of college students, was every 2 to 3 days using a rapid, cheap, high-specificity test (even if poorly sensitive).

Now, vaccination is clearly the most important tool for achieving a return to some semblance of normalcy. COVID-19 vaccines reduce infection, transmission, severe illness, hospitalization, and death. While breakthrough infections can occur, these are usually mild. A recent modeling study found that if campus vaccination coverage can be driven to over 90%, “campus activities can be resumed while holding cumulative cases below 5% of the population without the need for routine, asymptomatic testing.”

But many colleges and universities are very far from achieving a 90% coverage rate. Only 54% of 18- to 24-year-olds in the U.S. are fully vaccinated. There are many reasons for such low coverage — young people are less likely to be offered vaccination and even if offered, they may be hesitant “due to a reduced perception of individual risk and the inconvenience of making appointments.” Many parts of the U.S. still face high community infection rates, driven by the more transmissible Delta variant, and campuses cannot rely on vaccination alone to avert outbreaks.

But what about universities that have adopted vaccination mandates and have achieved very high coverage rates — can they relax other measures? Cornell and Duke were the first to adopt a mandate, and over 1,000 U.S. colleges and universities have followed suit. Vinay Prasad, MD, MPH, recently argued in MedPage Today that highly vaccinated campuses should abandon “strict COVID policies” such as masking and asymptomatic screening. On Twitter he went further, analyzing why college students have not mounted protests against COVID-19 policies just as they mounted protests against the Vietnam war — an analogy that we found derogatory.

The Public Health Benefits of Testing: A Case Study

With the backdrop of high community transmission rates driven by the Delta variant, a city-wide emergency declaration, and an indoor mask mandate, our university has continued its screening program, which we believe has been valuable. Early in this fall semester, it allowed us to identify an outbreak — in 1 week, 349 students and 15 employees tested positive; all but 8 were vaccinated.

While most infections were asymptomatic and nobody needed hospitalization, this type of uncontrolled transmission puts vulnerable people on campus at risk. For example, we have a number of students and employees who have had kidney transplants or have auto-immune conditions like rheumatoid arthritis who take immunosuppressant drugs and who may mount an inadequate antibody response to vaccination. We have older patients and staff who, despite being vaccinated, have severe comorbidities and could still get sick if they are infected with SARS-CoV-2. The recent death of Colin Powell, who was vaccinated, underscores the importance of protecting older people with comorbidities — Powell was 84 years old and had undergone treatment for multiple myeloma.

Detecting this surge in cases allowed Duke to institute additional measures to successfully drive down transmission, such as temporarily suspending indoor dining. This in turn helped reduce the likelihood of our university driving transmission into our surrounding communities. Four in 10 people in Durham are not fully vaccinated, including all children under 12 (vaccines are not yet authorized for this age group). Hospital staffing and bed occupancy are still under pressure from COVID-19, so we must continue to drive transmission rates down.

Surveillance also gave us visibility about new variants, acting as an early warning system. And North Carolina’s Department of Health and Human Services has told us that the testing and surveillance infrastructure that universities across the state have put in place will be valuable for managing future outbreaks.

We are also extremely fortunate to have the financial and technical capacity to be able to sequence the genomes of all positive cases, which has given us insights into transmission dynamics and the biology of SARS-CoV-2. We have had a unique opportunity to study such transmission in a highly vaccinated population and we will be studying these data for years to come. The data have already shown us where transmission is happening — such as in off-campus bars. With universal masking and upgraded ventilation, we have not documented a single case of classroom transmission, which has been reassuring.

Universities and medical schools are places of learning, teaching, research, and the generation of knowledge. They must look after the health of their students, instructors, service and maintenance staff, and communities. SARS-CoV-2 screening programs help to achieve these goals. Our experience has been that the overwhelming majority of students have been proud of being part of the program and saw the value to the broader Durham community of identifying a surge in cases and taking steps to turn around this outbreak.

Defining “Off Ramps”

Nevertheless, we recognize that the U.S. is not going to eliminate COVID-19, the disease will become endemic, and there will always be some level of infections and deaths. Universities, including ours, will need to define “off ramps” — that is, criteria for when it is appropriate to stop measures such as masking and screening. These are likely to be based on a combination of high population vaccination coverage, the end of the Delta surge, and low community transmission rates.

Campus COVID-19 testing programs are costly and there will come a time when they will no longer be needed. We are getting close. But right now, these programs are helping to keep communities safe and are generating valuable knowledge.

Gavin Yamey, MD, MPH, is a professor of global health and public policy at Duke University, where he directs the Center for Policy Impact in Global Health. Cameron Wolfe, MBBS, MPH, is an associate professor of medicine and an infectious disease specialist in the Division of Infectious Disease in the Department of Internal Medicine at Duke University Medical Center. Gregory Wray, PhD, is a professor of biology and director of the Duke Center for Genomic and Computational Biology at Duke University.