RESUMO
Immunogenicity of an experimentally prepared combined oil emulsified Escherichia coli-Pasteurella multocida [E. coli-P. multocida] vaccine was evaluated in susceptible chickens. The immune responses of vaccinated birds against monovalent E. coli, P. multocida and combined E. Coli-P. mutocida vaccines as estimated serologically using indirect haemagglutination test and ELISA test revealed no substantial differences with respect to the protective values between the monovalent and combined vaccines. The results of challerge test showed that vaccinated chickens could be effectively immunized with combined E. coli-P. multocida vaccine against challenge with E. coli and P. multocida virulent strains. In conclusion, this locally prepared vaccine was safe, immunogenic and protect chickens against E. coli and P. multocida infection