CD79A and COVID-19: At T5 (i.e., 4–6 weeks after dose 2 of COVID-19 mRNA vaccine), a reduction was observed in the anti-spike (median: 499 pM) and the anti-RBD (median: 0 pM) IgA response (Fig. 1a, b; Supplementary Fig. 2; and Supplementary Table 2).