EN
Evaluation of the immunogenicity of the vaccine against respiratory tract infections in calves caused by Pasteurella multocida, and prepared from antigen of a local strain of serotype 3 with oil adjuvant addition, was the object of the prescnt studies. Two experiments were carried out using calves. Vaccine was given them at a dose of 2 ml i.m., twice every 14 days. In experiment 1, sera were obtained before vaccination, 2 and 5 weeks after the first vaccination, in experiment 2 - before vaccination, 2 weeks, 1 and 2 months after the first vaccination. lmmunogenicity of the vaccine was evaluated by means of an agar gel immunodiffusion (AGID) test and an ELISA test. The carrier-state of Pasteurella multocida on mucous membrane of nasal cavity was examined. lt was found that immunisation stimulated the production of the specific precipitins for serotype 3 and it caused the increase of IgG level found using ELISA test with microplate coated with whole-bacterium antigen or LPS of that serotype. The investigation confirms the good immunogenicity of the vaccine.