CD79A and infection: As shown in Fig. 4a, b, significantly higher levels of IgA antibodies were observed in feces, in which IgA antibody responses were higher after challenge infection (Fig. 4b, χ2 = 8.0563, df = 2, P = 0.0178), compared to that before challenge infection (Fig. 4a; significant differences: χ2 = 8.1563, df = 2, P = 0.012,).