The obtained results indicate the possibility of creating proteins that have high immunogenic and protective properties and are based on fragments of IgA1 protease A28–P1004; the high degree of conservativity of the used fragments of IgA1 proteases from N. meningitidis, Neisseria gonorrhoeae and a number of strains of Haemophilus influenzae allows us to suggest that such a vaccine can effectively protect humans from infection with these pathogens. Here, IGHA1 is linked to infection.