Fig. 2

Antibody titres against SARS-CoV-2 in the first and third physical examination. A The titres of IgM in the first and third physical examination. B The titres of IgG in the first and third physical examination. The comparison of titres of IgM and IgG in the first and third physical examination was performed with Mann-Whitney U test. The sample sizes in the first and third physical examination were 183 and 159, respectively. Data are shown as min, Q25, Q50, Q75, and max value. *P < 0.001