Cut-off values: 1.00 COI for iFlash-2019-nCoV Antigen® (YHLO Ag) and 0.80 U/mL for Elecsys® Anti-SARS-CoV-2 immunoassay (Roche Diagnostics)
Table 3: Concordance between YHLO Ag and AAZ Ag Assays (ELISA, RDT).