Objective： To construct the recombined phage which was inserted with the gene of extracellular domain of chicken EGFR as a new type vaccine and to evaluate the efficiency of the phage vaccine against the EGFR positive tumor. Methods： The T7 phage display system was used to display 5 fragments of the extracellular domain of chicken EGFR. The EGFR was expressed as a fused protein on the surface of the T7 phage 10B capsid protein. The EGFR expression of the phage vaccine was verified by the Western blot analysis. The anti-EGFR antibody was detected by ELISA. The splenic lymphocytes of the immunized mice were separated and used to determine the cellular immunotoxic effect against A431 cells. The phage vaccines were injected into the C57 mice 4 times before lewis lung cancer cells were inoculated. The tumor volume was recorded to evaluate the anti-tumor effect of each vaccine. Results： Five phage vaccines inserted with the chicken EGFR gene were constructed successfully. Western blot assay showed that the extracellular domain of chicken EGFR proteins was displayed on the surface of the phage. The specific antibody was induced in the immunized mice compared with the control group. The splenic lymphocytes of the immunized mice were shown to be immunotoxic against A431 cells. The killing rates of the experimental groups were higher than in the control group （P〈0.001, by t test）. The highest killing rate was （45.74±7.21）%. The tumor growth was inhibited in the experimental groups as compared with the control group （P〈0.05 in C1, C2, C3 and C4 groups, P〉0.05 in C5 group）. Conclusion： The phage vaccine could induce both the protective and therapeutic antitumor immunity against EGFR-positive tumor.
