The mucosal surface is a natural point of entry for many respiratory pathogens such as influenza, Streptococcus pneumoniae, Mycobacterium tuberculosis, Staphylococcus aureus, B. anthracis, coronavirus, rotavirus, etc. Moreover, immunization at one mucosal surface, particularly intranasal vaccination in mice, monkeys, and humans has generated not only a local IgA response, but also enhanced the IgA response in salivary glands, upper and lower respiratory tracts, and even in distant genital tracts, and the small and large intestines [32,33,34,35,36,37]. Here, CD79A is linked to influenza.