Table 1.

Clinical performance of the agglutination-based antibody assay

Samples	Anti-S-RBD (n)		Anti-N (n)		Overall sensitivity	Overall specificity
	Positive	Negative	Positive	Negative
SARS-CoV-2 NAAT positive (n = 169)	166	3	164	5	98.2% (166/169)	n/a
Days of SARS-CoV-2 NAAT positive
1 (n = 41)	38	3	36	5	92.7% (38/41)	n/a
2 (n = 31)	30	1	31	0	100%	n/a
≥3 (n = 97)	97	0	96	1	100%	n/a
SARS-CoV-2 NAAT negative (n = 121)	0	121	0	121	n/a	100%
Pre-COVID-19 (n = 100)	0	100	0	100	n/a	100%