IGHG3 and COVID-19: Figure 5 demonstrates that IgG1 and IgG3 binding RBD- and S-proteins dominate among the IgG subclasses. This finding is consistent with the fact that these subclasses are associated with recovery and survival in COVID-19 serological studies [52]. It should be noted that the literature data on the analysis of IgG subclasses were obtained during acute SARS-CoV-2 infection, with IgG1 and IgG3 being the dominant IgG subclasses [53].