We found an increase in the COVID-19-specific antibody levels in human milk with booster vaccine doses, which was reflected by a positive relationship for the second (coefficient=0.91, P-value 0.043 for IgA and coefficient=1.77, P-value 0.009 for IgG) and third (coefficient=1.23, P-value 0.25 for IgA and coefficent=3.73, P-value 0.0068 for IgG) vaccine doses. This evidence concerns the gene CD79A and COVID-19.