Table 1. The positive detection rate of antibodies against COVID-19 Virus in different course of disease.

Days after onset	No. of samples	IgA			IgM			IgG			Neutralization antibody
		No. of positive samples	Detection rate (%)		No. of positive samples	Detection rate (%)		No. of positive samples	Detection rate (%)		No. of positive samples	Detection rate (%)
0–3	26	7	26.9		10	38.5		5	19.2		4	15.4
4–7	18	7	38.9		8	44.4		6	33.3		7	38.9
8–14	13	8	61.5		8	61.5		6	46.2		6	46.2
15–21	21	20	95.2		21	100.0		20	95.2		20	95.2
22–28	27	25	92.6		27	100.0		27	100.0		26	96.3
29–35	33	33	100.0		30	90.9		31	93.9		31	93.9
36–42	22	20	90.9		22	100.0		21	95.5		18	81.8
43–64	50	48	96.0		45	90.9		50	100.0		47	94.0
Total	210	168	80.0		171	81.4		166	79.0		159	75.7