In this study a double oil emulsion inactivated BEF vaccine mixed with Montanide ISA 206 was prepared. Studying the dynamics of serum antibody in vaccinated calves using of SNT and ELISA
showed that antibody titers reached level considered protective within two weeks and lasted for about 40 weeks. In conclusion, results of present study indicated that the vaccine formulated according to our procedures could provoke long lasting protective immune response after single dose administration, without inducing any adverse reactions.