Table 1.

ELISA performance statistics for plasma or serum IgG (Toronto)

	Spike	RBD	N	≥ 2 Positive antigens
ROC analysis
AUC	0.978	0.974	0.964	n/a
Threshold (cut point)	0.195	0.073	0.349	n/a
FPR	0.009	0.009	0.009	0.000
TPR	0.944	0.921	0.811	0.931
3 SDs from the mean of the negative controls
Threshold	0.190	0.186	0.396	n/a
FPR	0.011	0.000	0.007	0.000
TPR	0.944	0.890	0.786	0.912

Samples used to assess performance a
Sample cohort	Replicates	Number	Total
Patients with COVID‐19	1	211	392
	2	181
Pre‐COVID‐19 (negative)	1	300 for N and spike, 296 for RBD	560
	2	260 for N and RBD, 258 for spike

^a Negative samples were excluded from the analysis for spike and RBD if one replicate was positive.