The training manual is prepared in accordance with the program of the course "Fundamentals of Immunology" and contains all the current information on the discipline. The manual is illustrated with photographs and drawings. It comprehensively highlights current advances in molecular immunology. The structural organization of the immune system, the functions of cellular and humoral immunity, their relationship with non-specific protection factors are considered; as well as the mechanisms of the immune response and the formation of immunity in organ systems. The manual provides basic provisions on immunodeficiencies, autoimmune disorders, tumor immunology, aging, as well as infectious immunity. The textbook is intended for students of secondary vocational education and undergraduate studies.