CD79A and infection: When individuals with hybrid immunity (two-dose mRNA vaccine regimen + infection) were boosted with BBIBP-CorV, their anti-RBD IgG and anti-S IgA antibody levels were similar, but their anti-S1/S2 IgG level was halved (mean 85.8 neutr (%), 6.9 S/CO, 532.3 AU/mL, respectively) compared to group 2 individuals who received the same vaccine regimen (BNT162b2 + BNT162b2 + BBIBP-CorV) but were not infected between the second and third doses (mean 79 neutr (%), 5,7 S/CO, 1195.8 AU/mL, respectively).