CD79A and COVID-19: Figure 2B shows that 27 of 30 (90%) women had anti-RBD IgG above the positive cut-off value, with levels remaining positive in milk obtained D≥120 from all but one woman. Fifty-three percent of women tested positive for anti-RBD IgM following their positive COVID-19 test and 46% of women who provided milk during the four-month follow-up had positive RBD-IgM levels (Figure 2C). Although more women had IgG responses in their milk compared to IgA (90% vs 73%), the number of women having a high response, as defined by OD ≥ 0.5, was greatest for IgA (filled circles in Figure 2).