Fig. 3.

Titers of antibodies against SARS-CoV-2 in four COVID-19 patients at different days after symptoms onset. Levels of IgG (A) and IgM (B) antibodies against SARS-CoV-2 at different time periods after symptoms onset in four COVID-19 patients are plotted. The IgG and IgM antibody titers gradually increased up to the third week and decreased thereafter with a more dramatic decrease back to the titers of the first week in the IgM antibodies. The boxplots show medians and first and third quartiles, and the whiskers show minimal to maximal range below and above the box.