A proposed COVID Cohort model for re-opening college campuses when they reopen

Disclaimer: I am not an infectious diseases expert.  This proposal is not to be construed as an official recommended course of action. This proposal has not been reviewed by infectious disease experts, and this article is a means of seeking feedback from experts and non-experts alike on the viability and likelihood of success of this proposal.

Faculty at George Mason were asked for any input on the re-opening models being trade-studied for fall 2019.  This is my edited response:

A Proposed "COVID Cohort" Model for Re-opening College Campuses in Fall 2020

This proposed cohort model does not eliminate the need for facemasks, cleaning and santitation, and other social distancing measures in common areas as recommended by draft CDC guidelines.  This model supplements those approaches.  This model is under the assumption that we re-open campus to a significant fraction of students and staff; whether or not we re-open campus and under what criteria is beyond the scope of what is discussed here.

The goal of social distancing is to minimize the number of close social interactions we have to reduce the rate of community spread of COVID-19.

A plan to re-open a college campus should maintain similar goals.

Under a normal academic schedule at a typical US college, a college student, let's call her Alice, may take 5 classes of an average of approximately 30 students each.  Overlap of students enrolled between classes, particularly for freshman taking general education courses, can be a small number or zero.  In other words, if Alice and Bob both take ENG 101 together, the odds of them taking a second class together is low. Thus on a weekly basis, a single student like Alice can come into close social contact in their courses with approximately 150 peer students on average (and likely more given large lectures). In the presence of viral community spread, if Alice contracts COVID-19, Alice can potentially spread coronavirus in normal (pre-COVID-19) classrooms to approximately 150 (or more) other students.

[Edit: A recent network study by Cornell highlights that a single student can via three student interactions come into indirect contact 98% of a college student population under the pre-coronavirus status qup: https://www.insidehighered.com/news/2020/04/14/sociologists-say-their-findings-student-interconnectedness-suggest-caution-needed ]

If, however, a University implements a "cohort" model - a group of students that take classes together - we can reduce the rates of coronavirus spread by factors of approximately up to five in this toy model.  If instead Alice takes the same 5 classes with the same 30 students, and if Alice contracts coronavirus, Alice can now only spread coronavirus to 30 students instead of 150 within the classroom setting.

Thus, I recommend college campuses consider a COVID cohort option for re-opening in the fall.  We want to maximize the number of classes students take together in person in common to minimize the number of distinct physical social interactions a student has. This is entirely aligned with the draft CDC guidelines for childcares and schools re-opening:

"Ensure that student and staff groupings are as static as possible by having the same group of children stay with the same staff(all day for young children, and as much as possible for older children).  

Restrict mixing between groups."

This will be a challenge to implement - students are currently given the freedom to choose classes independently to suit their schedules, and in fact registration has already begun at many campuses for the fall semester.  However, we know when freshman take general education courses, many have similar courses in common albeit in different sections or large lectures.  Additionally, for upper-class students with declared majors, many take classes inside their major together.  Unfortunately, we have already passed the time when students have started registering for classes, and so we may limited to identifying cohorts from students already enrolled in courses together.

I would like to propose that upper-class students based upon their declared majors and year be placed into cohorts by academic advisors familiar with students academic progress to  take the same courses together for the fall 2019 semester, and to request students minimize or take online only classes for the classes that they can not take with their cohort.  For example, junior physics majors could be a "cohort", and if they take any classes outside of their major-year cohort, they must take them virtually online.  In addition, to all extents practical, cohorts should take all of their classes in the same physical classroom, since the virus can also spread via surfaces.

Similarly, for freshman that have many classes in common, may I propose that their schedules be divided into cohorts based upon general education course sections of ~30 people and their expressed majors or undeclared interests.  Again, if freshman students take non gen-ed classes outside their cohort or declared major, they be required to take those classes virtually or online.  Another cohort could be honors college students, for example, again organized by class year, and college or major for declared students.  Students that live off campus could potentially be given a separate cohort designation from those that live on campus, especially given that students that live off campus are more likely to have additional social/work interactions off campus and outside the campus community. Students can also be given the option of choosing cohorts that are entirely online, particularly students that have underlying conditions or concern of contracting the virus.

To promote the adoption of these student cohorts of ~30 people in size, may I suggest that the face masks a University will hopefully be providing to students be given colors or University symbols of pride or chosen major symbols that let students easily identify when they are among students from their cohort or not.

For freshmen and students living on campus, they could be physically located in dorms aligned by cohort, so that the social interactions of students outside of class will be similar to the students they have in their classes.

The cohort model has been shown to promote retention of students (like in live-and-learn communities), and having students take the same classes together and live together could lead to overall better academic outcomes during these times of a pandemic crisis. Some programs already on campus have identified cohorts (like the honors college).   The cohort model for education for retention and identity building has a strong and positive academic heritage.  Organizing classes / dorms around a cohort model to the practical extent possible could both be touted as a positive education approach in higher ed and have real benefits in limiting virus communal spread.

Additionally, cohort model will help with contact tracing and mitigation for cases that do appear on campus.  Freshman moving onto campus should be encouraged to come to campus two weeks before the start of the semester, and then isolate together in their new cohort.  At the end of the two weeks, they can be tested and begin instruction.

In the era of limited testing capabilities, if a member of a cohort during the semester comes down with coronavirus symptoms or tests positive for coronavirus, the entire cohort can self-quarantine, and be put on required virtual instruction while the rest of campus can continue uninterrupted.  Members of cohorts can be periodically tested for coronavirus as representative samples.

This type of approach would be easier to implement if all professors teaching in person classes also recorded their classes for posting online and for remote participation.  The faculty, which will teach 2-4 classes, can still get infected as well, and spread the virus to all of their students.  So faculty and staff will have to take extra social distancing measures - not handing out printed materials but using digital materials and exams only, for example - to avoid spreading the virus from classroom to classroom.

Finally, elementary schools naturally arrived at the cohort model for organizing student education, by having the same students take the same set of classes, sometimes in the same room with teachers rotating through classrooms.  There is precedent for a cohort model in education in general and higher education specifically.