Fig 1. Overview of our university COVID monitoring program and workflow.

(A) Map of Ohio with locations of the six university campuses which participated in the COVID monitoring program. Original map source: Wikimedia Commons [111]. (B) On and prior to the day of testing, each individual assessed themselves for one or more COVID symptoms (see Methods). If symptomatic, the individual was given a clinical referral and instructed to not go to their on-campus testing facility, to prevent contagion. If asymptomatic, the individual provided a saliva sample which was tested (typically within 24 hours of sample provision) via qRT-PCR for the presence of the CoV2 N gene. Individuals were notified as soon as possible as to whether their sample was negative (PCR^NEG) or positive (PCR^POS) for the virus, a positive result being a C_T ≤ 40. PCR^POS samples were subsequently aliquoted and used for both CoV2 lineage identification and measuring the concentrations of immunoglobulin against specific CoV2 antigens (CoV2-Ig). The vast majority of PCR^NEG samples were discarded; however, a minority were retained and used for CoV2-Ig measurements. PCR^POS and PCR^NEG samples were otherwise treated identically.