Extended Data Figure 3. Test characteristics for the ELISpot SARS CoV-2 assay.

A. Receiver operator characteristic (ROC) curves for individual results for spike pool A, B, and the nucleocapsid peptide pools utilizing data from the convalescent and healthy donor subjects in Figure 1. Area under the curve (AUC) is shown for each ROC. B. Evaluation of SFU positive threshold for responses to either spike A or to spike B pools as a combined output versus sensitivity and specificity. Red asterisk represents the selected threshold to optimize the tradeoff between sensitivity and specificity. Convalescent patients had a median SFU of 16.0, 95% CI [9.5–38.5] for spike pool A, 21.5 [17.0–35.0] for spike pool B, and 23.5 [12.0–36.0] for the nucleocapsid pool, compared to 0.5 [0.5–1.5], 2.5 [0.5–3.5], and 0.0 [0.0–1.0] in the healthy controls.