Figure 3.

(A) The BRAVO clinical validation study included pre-COVID samples (collected prior to December 2019) as negative controls and saliva from PCR-confirmed COVID-19 patients as the positive control. The 30 negative control samples used to determine a cut-off for muco-positivity as described in the methods. One false positive (green dot) had readings above the cut-off. Of the 38 COVID-19 subjects, three (red dots) has salivary IgA levels below the cut-off and were deemed to be False Negative results.