Morphological indexes in immune system organs of piglets which were vaccinated which were immunized by SPS vaccine (against salmonellosis (Salmonella), pasteurellosis (Pasteurella) and streptococcus) in combination with immunostimulative drugs and without them were studied in the conditions of the Republic of Belarus. Piglets of the first group were vaccinated against salmonellosis, pasteurellosis and streptoccocusis by SPS vaccine. Piglets of the second group were vaccinated by SPS vaccine in combination with vitamin C. Piglets of the third group were vaccinated by SPS vaccine with immunotstimulant sodium thiosulphate. The fourth (control) group of animals was administrated with normal saline. Animals were immunized twice, intramuscularly with 7 day interval and in dose 4 ml (primary), 5 ml (secondary). Vitamin С was added in dose 0,05g per head. Research results showed that immunization by SPS vaccine with sodium thiosulphate and Vitamin С activated the morphological reaction of immune system. Application of Vitamin С and sodium thiosulphate (30% concentration) in combination with SPS vaccine promoted the increasing of lymphoid nudels in lymphodnudus and lien, increasing of plasma cells quantity in 1,3-2,2 times, activation of micro- and macrophage reaction in 1,5-2,8 times in comparison with vaccinated animals

Determination of a degree of manifestation of immunomorphological changes in immune system organs of piglets vaccinated against salmonellosis, pasteurellosis and streptoccocusis with SPS vaccine (against salmonellosis (Salmonella), pasteurellosis (Pasteurella) and streptococcus) in combination with immunostimulative drugs and without them was realized in the conditions of the Republic of Belarus. Piglets of 30-35 days old were divided into 4 groups according to the analogue principle. Piglets of the first group were vaccinated against salmonellosis, pasteurellosis and streptoccocusis by SPS vaccine. Piglets of the second group were vaccinated by SPS vaccine with vitamin C. Piglets of the third group were vaccinated by SPS vaccine with immunotstimulant sodium thiosulphate. The fourth (control) group of animals was administrated with normal saline. Animals were immunized twice, intramuscularly with 7 day interval in dose of 4 ml (primary), and 5 ml (secondary). Vitamin С was administrated in dose of 0,05g per head. Sodium thiosulfate was administrated in combination with the vaccine in 30% concentration. The research results showed that immunization with SPS vaccine in combination with sodium thiosulphate and vitamin С promoted the activation of morphological reactions in tissues at locus of vaccine administration, lymphodnudus and lien. Immunization of piglets by SPS vaccine with sodium thiosulphate and with vitamin С activated the limphiod, micro- and macrophage reactions at locus of vaccine administration, as well as in organs and cells there was stated the well-marked vitamin C and glycogen distribution. Sodium thiosulphate showed higher immunostimulate influence in comparison with vitamin C