Objective: Poultry Colibacillosis caused by different Avian Pathogenic E.coli (APEC) serotypes that accompanied by different symptoms and commercial loses in poultry industry. Different works were done to control disease by vaccination with live attenuated, killed, recombinant and DNA vaccine. In this study the cellular immune response of a newly candidate homologous vaccine against E. coli O2:K1 that have produced by use of bacterial ghost technique was evaluated. Materials & Methods: To assessment the influence of this produced candidate vaccine on cellular immune responses, 85 one day old chickens from Ross 308 breed were divided into the following 5 groups; group 1 (non-immunized control), group 2 (vaccine administered by injection of E. coli O2:K1 killed vaccine), group 3 (vaccine administered by injection of E. coli O2:K1 ghost), group 4 (vaccine administered by inhalation of E. coli O2:K1 ghost), and group 5 (neither immunized, nor challenged as negative control). The three groups of 2, 3, and 4 were received vaccines at days 7, 14, and 22. Groups 1 to 4 were challenged with the wild serotype at day 33. Sampling were done at days 14, 25 and 38. Evaluation of cellular immune response was done by measuring levels of γ IFN in serum samples by direct sandwich ELISA technique. Results & Conclusions: Results showed that chickens injected with the bacterial ghost and the killed vaccine had the higher level of γ IFN compare to non-vaccinated chickens (P<0/05).

Keywords