ABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic prompted universities across the United States to close campuses in Spring 2020. Universities are deliberating whether, when, and how they should resume in-person instruction in Fall 2020. In this essay, we discuss some practical considerations for the use of two potentially useful control strategies based on testing: 1) SARS-CoV-2 RT-PCR testing followed by case-patient isolation and quarantine of close contacts, and 2) serological testing followed by an "immune shield" approach;i.e., low social distancing requirements for seropositive persons. The isolation of case-patients and quarantine of close contacts may be especially challenging, and perhaps prohibitively difficult, on many university campuses. The "immune shield" strategy might be hobbled by a low positive predictive value of the tests used in populations with low seroprevalence. Both strategies carry logistical, ethical and financial implications. The main non-pharmaceutical interventions will remain methods based on social distancing (e.g., capping class size) and personal protective behaviors (e.g., universal facemask wearing in public space) until vaccines become available, or unless the issues discussed herein can be resolved in such a way that using mass testing as main control strategies becomes viable.