Rutgers Pilot for Pragmatic Return to Effective Dental Infection Control Through Triage and Testing (PREDICT)- Dental Health Care Workers

10 asymptomatic DHCWs in the Oral Medicine clinic, Rutgers School of Dental Medicine, with no history of documented COVID-19 infection or viral exposure, were enrolled in the DHCW arm of the study. The DCHWs underwent triage that included self-reported symptoms, temperature check and obtaining a pulse oximeter reading at every study time-point (See DHCW Arm in Results Section). Weekly Rapid Antigen testing of nasal swab specimens was used to document Antigen negativity during the study (BD Veritor Plus Analyzer, BD Sciences). The DHCWs' perceptions of safety and adoption of risk mitigation behavior were interrogated. Following a baseline survey, finger-prick blood samples were collected twice two weeks apart using avolumentric absorptive microsampling with a Neoteryx Mitra cartridge device (https://www.neoteryx.com) device that allows for self-sampling by non-specialized personnel (https://doi.org/10.1101/2021.07.09.21260266). Briefly, this microsampler allows for volumentric absorption of 10-30 μl of blood depending on selected size. Following the collection, microsamplers were dried and kept within the protective cassettes at room temperature for maximum period of 2 weeks from the collection date. Each microsampler tip (20µl in the present study) was added to 200 μl VAMS extraction buffer (1x PBS (Corning) supplemented with 1% bovine serum albumin (Roche Diagnostics, Mannheim, Germany) and 0.5% Tween20 (Sigma, MO, USA) in a 1 ml deep-well 96 well plate (Greiner bio-one-780261). The plate was then covered with an adhesive seal and incubated 16 hours at 40C on a shaker at 250 rpm. The resulting eluates were heat inactivated at 560C for 60 minutes and centrifugation to collect the supernatant (eluate). Eluates were further processed for an in-house ELISA assay to detect IgM and IgG directed against the Receptor Binding Domain (RBD) of the SARS-CoV-2 Spike protein as described (https://doi.org/10.1101/2021.07.09.21260266)..