[Discovering of mucosal immunity].

The mucosal surface area of gastrointestinal, respiratory and urogenital tracts of an adult individuals is about 400 m2 and is the main route of infection and potential harmful agents penetration. It emphasize the essential role of the mucosal immune system (MALT). The beginnings of mucosal immunology, based on the people's observations and believes, descent from ancient times, when the attempt of immunization of human organism against distressed illness have been undertaken. Discovery of a MALT system elements and mechanisms of the mucosal immunity working occured in the 20th century. At that time, the base of beneficial properties of human and other animals' secretions have been recognized, starting from milk, through saliva, ending to feces. Nowadays, it is known, that in all secretions, beside innate defence, the main part of mucosal immunity perform antibodies synthetized locally, with the predominance of the class A (IgA). In this paper the greatest discoveries, leading to the understanding of mucosal immunization resulting in systemic resistance, have been approached.