Table 1.

Characteristics of the specimens that were discordant among the Mindray CL-900i anti-SARS-CoV-2 IgG, BioMérieux VidasIII anti-SARS-CoV-2 IgG, and Roche Elecsys Anti SARS-CoV-2 antibody testing.

Specimen number%	Record of PCR positive test prior to study£	Date of blood and naso-pharyngeal swab specimens’ collection at time of study	PCR test at time of study		Mindray CL-900i anti-SARS-CoV-2 IgG*		BioMérieux VidasIII anti-SARS-CoV-2 IgG**		Roche Elecsys anti SARS-CoV-2***		Symptomatic at time of study#	Severity at or right after time of study$
	Test result		Test result	Ct value	Optical density	Test result	Optical density	Test result	Optical density	Test result
20	N/A	10-Aug-20	Negative		3.76	Negative	5.86	Positive	0.48	Negative	No	N/A
21	N/A	10-Aug-20	Negative		111.72	Positive	0.45	Negative	67.27	Positive	No	N/A
22	N/A	6-Aug-20	Positive	21.62	3.74	Negative	0.10	Negative	8.40	Positive	Symptomatic	Severe
29	N/A	27-Jul-20	Negative		5.81	Negative	1.08	Positive	5.62	Positive	No	N/A
37	N/A	10-Aug-20	Negative		7.77	Negative	0.47	Negative	3.66	Positive	No	N/A
40	N/A	29-Jul-20	Negative		20.24	Positive	0.01	Negative	0.16	Negative	No	N/A
50	N/A	11-Aug-20	Negative		31.25	Positive	0.04	Negative	0.09	Negative	No	N/A
61	N/A	29-Jul-20	Negative		135.05	Positive	0.45	Negative	38.01	Positive	No	N/A
71	N/A	28-Jul-20	Negative		4.17	Negative	0.88	Negative	3.01	Positive	No	N/A
82	N/A	10-Aug-20	Negative		71.76	Positive	0.02	Negative	0.08	Negative	No	N/A
126	N/A	10-Aug-20	Positive	26.95	10.50	Positive	0.15	Negative	0.18	Negative	No	N/A
128	N/A	10-Aug-20	Positive	33.81	220.63	Positive	0.62	Negative	7.72	Positive	No	N/A
129	N/A	10-Aug-20	Negative		16.60	Positive	0.07	Negative	0.08	Negative	No	N/A
131	N/A	13-Aug-20	Positive	28.32	36.22	Positive	0.46	Negative	9.23	Positive	No	N/A
137	N/A	10-Aug-20	Negative		4.72	Negative	0.46	Negative	10.98	Positive	No	N/A
147	N/A	10-Aug-20	Negative		39.57	Positive	0.94	Negative	10.92	Positive	No	N/A
174	N/A	29-Jul-20	Positive	24.09	12.05	Positive	1.29	Positive	0.12	Negative	No	N/A
182	N/A	29-Jul-20	Negative		11.22	Positive	0.35	Negative	0.07	Negative	Not reported	N/A
191	N/A	10-Aug-20	Negative		7.87	Negative	1.75	Positive	8.41	Positive	No	N/A
213	N/A	29-Jul-20	Negative		140.62	Positive	0.00	Negative	0.11	Negative	No	N/A
223	N/A	10-Aug-20	Negative		7.29	Negative	4.73	Positive	7.35	Positive	No	N/A
228	N/A	10-Aug-20	Negative		0.17	Negative	5.56	Positive	40.35	Positive	No	N/A
232	N/A	29-Jul-20	Positive	23.89	16.48	Positive	0.19	Negative	0.09	Negative	No	N/A
246	N/A	10-Aug-20	Negative		5.60	Negative	1.37	Positive	6.98	Positive	No	N/A
255	N/A	27-Jul-20	Negative		8.06	Negative	1.09	Positive	10.18	Positive	No	N/A
280	N/A	29-Jul-20	Positive	32.34	20.61	Positive	2.30	Positive	0.51	Negative	No	N/A
296	N/A	27-Jul-20	Negative		15.7	Positive	0.04	Negative	0.15	Negative	No	N/A
319	N/A	29-Jul-20	Negative		4.07	Negative	2.48	Positive	1.16	Positive	No	N/A
328	N/A	29-Jul-20	Negative		6.41	Negative	0.68	Negative	2.59	Positive	No	N/A
337	N/A	29-Jul-20	Negative		80.22	Positive	0.86	Negative	5.62	Positive	No	N/A
355	N/A	29-Jul-20	Positive	29.18	2.36	Negative	2.11	Positive	0.10	Negative	No	N/A
357	N/A	29-Jul-20	Negative		10.49	Positive	3.34	Positive	0.73	Negative	No	N/A
360	N/A	10-Aug-20	Negative		13.57	Positive	0.06	Negative	0.09	Negative	No	N/A
376	N/A	10-Aug-20	Negative		45.70	Positive	0.07	Negative	0.09	Negative	No	N/A
387	N/A	11-Aug-20	Positive	24.24	310.78	Positive	0.46	Negative	4.56	Positive	No	N/A

Ct cycle threshold, N/A not applicable, PCR polymerase chain reaction.

*Mindray CL-900i anti-SARS-CoV-2 IgG assay positive: optical-density cutoff index ≥ 10.0 vs. negative: cutoff index < 10.0⁶.

**BioMérieux VidasIII assay positive: optical-density cutoff index ≥ 1.0 vs. negative: cutoff index < 1.0⁷.

***Roche Elecsys Anti SARS-CoV-2 assay positive: optical-density cutoff index ≥ 1.0 vs. negative: cutoff index < 1.0⁵.

^%Specimen number consistent with Supplementary Table S1 in Supplementary Information.

^£Date of first positive swab and Ct value are not available as there was no record for a prior positive swab for these specimens.

^#Symptoms as reported in the medical record for this infection.

^$Severity per WHO classification¹⁹. If N/A, no severity classification was conducted due to absence of serious symtoms to require hospitalization and severity assessment.