In addition to maternal antibodies, breast milk contains other immunomodulatory mediators, including activated T cells and memory T cells, secretory IgA, oligosaccharides, antibacterial proteins such as lactoferrin, lysozyme, beta-lactoglobulin, casein and pro- and anti-inflammatory factors that confer passive protection against incidence and severity of respiratory infections [241]. This evidence concerns the gene CD79A and respiratory tract infectious disorder.