Table 3.

Positive rate of anti-SARS-CoV-2 IgG antibody according to the different kits used.

IgG antibody
Days after onset	No. of samples	Hangzhou AllTest		SD BIOSENSOR		Vazyme
		No. of positive samples	Positive rate (%)	No. of positive samples	Positive rate (%)	No. of positive samples	Positive rate (%)
0–4	11	3	27.3	3	27.3	3	27.3
5–9	26	11	42.3	11	42.3	10	38.5
10–14	29	24	82.8	23	79.3	22	75.9
15–19	24	24	100.0	23	95.8	23	95.8
20–35	9	9	100.0	9	100.0	9	100.0
After 13	42	42	100.0	41	97.6	41	97.6
Total	99	71	71.7	69	69.7	67	67.7

The positive rate of both IgM and IgG antibody was the same as the positive rate of the IgG antibody.