[Comparative estimation of immunogenicity of anti-salmonellosis vaccines]

Immunogenicity of four vaccines against salmonellosis was studied on 30-day old pigs. Pigs were immunized twice at an interval of 10 days: group 1 – with a live dry vaccine from strain TS-177; group 2 – with a live vaccine from suppressor revertant Salmonella choleraesuis N9; group 3 – with an inactivated emulsive vaccine; group 4 – with an associated polyvalent vaccine against salmonellosis, pasteurellosis and enterococcus septimecia of pigs followed by infection with the pathogenic strain S. choleraesuis N264 in a dose of 1.5 ml intranasally and parenterally. All the vaccines caused in the immunized pigs a change in the level of leucocytes and their phagocytic activity, specific antibodies to O- and H-antigens, gamma and beta-globulins. The most immunogenic was the live vaccine from suppressor revertant Salmonella choleraesuis N9. When administered, the most pronounced immunological restructure characterized by: increasing the level of O- and H-agglutinins at day 10 after the first administration of the vaccine – 1:186 and 1:40, respectively, reaching the maximum at day 15 after the second vaccination – 1:320 and 1:333, respectively, intensive synthesis of gamma and beta-globulins. The group 2 pigs had an increase in phagocytic activity and phagocytic index since day 5 after the first vaccination, leucocytes, T-cells, B-cells compared to the control. In 3 weeks after revaccination by weaning the pigs of group 2 had increased values of leucocytes, lymphocytes, T-cells, B-cells, gamma-globulins, phagocytic activity and phagocytic index. The incidence of pigs in group 2 after experimental intramuscular and intranasal infection was 20 and 20%, respectively, compared to group 1- 40 and 40%, group 3 – 60 and 40% and group 4 – 60 and 60%. It is concluded that the immune activity of the vaccine from suppressor revertant Salmonella choleraesuis N9 was 80%. The readministration of antigens caused no rapid enhancing the immune response for live and inactivated vaccines