In successive paired serum samples, a decrease of IgM titer or an increase (more than four-fold) of IgG titer, or both can characterize a recent infection [22]. IgM usually disappears within 30 to 168 days after infection, while IgG can persist for years [39]....
In order to better understand the pathophysiology of COVID-19, it is vital to understand the immune responses against SARS-CoV-2 and how different antibodies are generated during infection. Information on the onset, peak and persistence of various antibodies is useful in evaluating host immunity ag...