EN
The examinations were carried out on 20 sheep of which 12 animals were immunized in the second half of pregnancy, 5 were infected and 3 served as controls. All the lambs (17) coming from the sheep were infected with virulent strains of L. monocytogenes (aged 8 weeks) to assess the state of immunity acquired from mothers. For immunization an attenuated vaccine prepared by the authors was used. Sheep and lambs were examined clinically, immunologically, bacteriologically and at necropsy. It was found that vaccinations with the vaccine developed the immune response of humoral and cellular type. The level of agglutinins in the immunized sheep was higher than that in controls. An increase of phagocytosis of neutrophils expressed in the tests of chemiluminescence and NBT pointed to a high reactivity of neutrophils following vaccination. An increased index of blastic transformation of lymphocytes took place after two weeks since immunization until the end of observations. Biological tests indicated that an active immunization of sheep in the second half of pregnancy influenced the immunity of mothers and their offspring.