Table 1. Performance of serial antibody assays, King County, Washington anti-SARS-CoV-2 seroprevalence survey, August 2020.

Test	Negative percent agreement (specificity)	Positive percent agreement (sensitivity)
Bio-Rad Ab test [9]	99.56%	92.16%
EuroImmun ELISA (IgG) [10]	100%	90%
Sequential Test [11]	100%	82.94%