CD79A and COVID-19: Levels of IgA and IgG in patients with severe COVID-19 were significantly higher than maximum levels obtained in infected HCWs [IgA: 9.59 (5.10–26.89) vs. 1.82 (1.37–3.29) respectively, p < 0.0001; IgG: 9.75 (8.05–10.75) vs. 1.12 (0.52–3.24) respectively, p < 0.0001] (Figures 4E,F).