Table 1. Antibody levels and kinetics in 20 PCR-confirmed SARS-CoV-2 infected patients.

	First week			Second week			Third week			Fourth week or later
Patient	Day*	IgG	IgA	Day*	IgG	IgA	Day*	IgG	IgA	Day*	IgG	IgA
1	–	–	–	8	0.2	0.4	15	4.5	5.3	22	5.4	4.9
2	6	0.5	1.3	13	1.5	3.5	20	2.6	3.6	28	2.7	3.0
3	–	–	–	9	0.3	0.3	16	6.2	5.6	23	6.6	5.1
4	7	0.3	0.3	–	–	–	16	5.6	7.7	–	–	–
5	–	–	–	12	6.7	8.1	19	9.0	8.1	26	10.0	7.3
6	–	–	–	10	0.3	0.3	17	4.1	7.6	24	8.4	7.6
7	–	–	–	12	0.6	1.4	–	–	–	27/43	1.2/1.6	1.7/1.7
8	–	–	–	14	1.7	3.5	–	–	–	29/45	4.1/3.7	5.7/3.8
9	–	–	–	13	0.9	2.9	20	1.4	4.0	27	5.5	7.4
10	7	0.3	0.4	14	6.9	7.8	21	7.3	7.8	–	–	–
11	–	–	–	8	0.8	5.1	15	4.1	7.8	22	7.3	7.6
12	4	0.2	0.1	11	1.0	6.8	18	5.5	7.0	–	–	–
13	6	0.3	0.4	13	0.8	1.5	20	2.0	2.4	35	2.0	1.9
14	–	–	–	8	0.5	7.6	15	0.5	6.1	24	0.5	3.7
15	–	–	–	–	–	–	20	7.6	7.7	27	9.3	7.3
16	5	0.2	0.5	12	1.0	2.7	19	4.9	4.2	–	–	–
17	7	0.8	2.5	–	–	–	15	8.4	8.0	22	8.4	8.0
18	–	–	–	–	–	–	–	–	–	22/36	1.1/1.3	2.5/2.2
19	1	0.2	0.4	–	–	–	20	3.36	6.2	–	–	–
20	–	–	–	–	–	–	–	–	–	27	5.3	7.0

*time point of serum sampling in days after disease onset (for the one asymptomatic case after positive PCR).