Evaluation of the immunogenicity of the vaccine against Pasteurella multocida infections in calves

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.