Prevalence of previous SARS- CoV-2 infection	False-positive rate
	Cellex test (sensitivity = 94%; specificity = 96%)	Hypothetical SARS-CoV-2 antibody test (sensitivity = 90%; specificity = 99%)
1%	80.8%	52.4%
5%	44.7%	17.4%
10%	27.7%	9.1%
20%	14.5%	4.3%
30%	9.0%	2.5%
50%	4.1%	1.1%
70%	1.8%	0.5%
90%	0.5%	0.1%