The object of the study is the immunological reactivity of rabbits for the use of "Vaccines against myxomatosis of rabbits dry living cultures of the strain" B-82 "" while simultaneously introducing the immunomodulator "Ribotan". The aim of the work was to study the epizootic situation regarding myxomatosis in private farms of the Odessa region and the immunological reactivity of the rabbit organism for the use of live vaccine with the simultaneous introduction of the immunomodulator "Ribotan". Research methods are epizootiological (monitoring epizootic situation), immunological (determination of the content of T- and B-lymphocytes), biochemical determination of the content of total protein, protein fractions), hematological, histomorphological, cytological and statistical methods. The seasonal dynamics of rabies disease for myxomatosis in the Odessa region is determined. Established prolonged action of the immunomodulator "Ribotan" 6 months after the revaccination and stimulation of humoral and cellular immunity. Simultaneous administration of the vaccine against myxomatosis and Ribotan leads to a steady increase in the level of γ-globulins in serum from rabbits for 6 months, indicating a positive effect on the body's immune-modulating preperation resistance. Found that "Ribotan" is a powerful stimulator of hematopoietic function. The relative number of T- and B-lymphocytes increases in vaccinated animals for 6 months from the 6th day after immunization and after revaccination, it is significantly higher in the groups using the Ribotan immunomodulator. After a general increase in the number of B-lymphocytes in 3 and 6 months in the experimental rabbit group, these indices were higher by 33.8 % than in the rabbits only of the vaccine, which is an indicator of stimulation of the synthesis of antibodies to humoral protection of the macro-organism. Cytological studies of fingerprint smears from the immune competent organs of the thymus, spleen, and regional lymph nodes showed a stable and sustained increase in immunocompetent cells in groups that were immunized from the 6th day of vaccination and reimmunization. Histological studies of immunocompetent organs (thymus, spleen, regional, lymph nodes) with the use of live vaccine with Ribotan immunomodulator, indicated active processes associated with the synthesis of immunocompetent cells, in particular, with the parameters of plasmaphasing of pulpal grafts, lymphoid infiltration of the hypodermic brain sinuses lymph node at the same time using a live vaccine and a Ribotan immunomodulator. Histological studies of immunocompetent organs (thymus, spleen, regional, lymph nodes) with the use of live vaccine with Ribotan immunomodulator, indicated active processes associated with the synthesis of immunocompetent cells, in particular, with the parameters of plasmaphasing of pulpal grafts, lymphoid infiltration of the hypodermic brain sinuses lymph node at the same time using a live vaccine and a Ribotan immunomodulator. Novelty: for the first time, a comprehensive study of immunological reactivity, histomorphological and cytological changes of immunocompetent organs of rabbits was carried out with the use of "Vaccines against myxomatosis of rabbits dry living cultures of the strain" B-82 "" while simultaneously introducing the immunomodulator "Ribotan". The scientific novelty of the dissertation is confirmed by obtaining a patent of Ukraine for utility model No. 1155520 "A method of specific immune prophylaxis of rabies myxomatosis" dated March 10, 2017. The main provisions of the dissertation work are described in the "Recommendations on the immunization of rabbits against myxomatosis" (Odesa, 2016). The scheme of use of the immunomodulator "Ribotan" has been developed in the course of vaccination of rabbits against myxomatosis, which involves simultaneous administration with the vaccine intramuscular injection into the thigh area at a dose of 1.0 cm3. The results of experimental research are used in practical and research work and educational process for students of educational degree "Bachelor" and "Master" in the specialty "Veterinary Medicine" at the Department of Epizootology and Parasitology, Odessa State Agrarian University.
