Postvaccinal dynamics in opson-phagocytic re- action, the number of T- and B-lymphocytes in the blood and the increase in the titer of specific anti- bodies of agglutinins in foxes immunized with live and inactivated vaccines against salmonellosis were studied. From young growth of silver-black foxes (Vulpes Vulpes) aged 60 days, bred in JSC "Spheroplast "Vyatka" (Kirov Region), 3 groups were formed (1 - animals vaccinated using inacti- vated vaccine against salmonellosis, 2 - live) and the control group (not vaccinated foxes). The ani- mals were taken blood from on the 7th, 14th, 21st and 28th days after immunization. In the response to the introduction of vaccine antigen in the body, there was consistent step-by-step activation of im- mune system: first, the capture of the antigen by macrophages; second, the proliferation and differ- entiation of T-cells, then the activation of B-cells and the production of specific antibodies and their natural reduction. Phagocytic activity of neutrophils in opson-phagocytic reaction in foxes after admin- istration of the vaccine increased by 7th day of the study, and by 21st day reached its maximum val- ues. The values of T-lymphocytes in immunized foxes increased to the maximum by the 14th day after vaccination, B-lymphocytes - by the 21st day. Then the number of T-and B-lymphocytes was re- duced by the 28th day of observation. The increasein antibody titer of agglutinins in reaction of aggluti- nation was traced. After the introduction of live vac- cine, all these indicators were significantly higher than after the immunization of animals with inacti- vated analogue. Live vaccine had more immuno- genic properties than its inactivated counterparts,i.e. live vaccine was most active in anti-gene impact on the organism of animals.