EN
The objectives of the study were examine immunological processes developing in mice in experimental Yersinia enterocolitica infection. The studies were performed on the BALB/c mice infected perorally with 10s live virulent cells of Y. enterocolitica. The activity of neutrophils, macrophages, lymphocytes T and В was evaluated in appriopriate tests. The dynamics of anti Y. enterocolitica antibodies was determined by agglutination and by indirect immunofluorescence test. It was found that in mice in the course of experimental yersiniasis both cellular and humoral immunity play an important role in protection but in various periods after infection. Cellular immunity develops earlier after about 6—9 days since infection but humoral immunity appears by about 12—15 day since infection.