ABSTRACT
Background: As avian influenza A/H5N1 epidemic spreads rapidly, many corporations, vaccine manufacturers in cooperation with laboratories around the world has conducted research and developed H5N1 vaccine for both humans and poultry. Objective: Evaluate the adaptation and cloning of rgh5n1 vaccine reference strain to vero cells in order to produce master seed virus and working seed virus. Subject and Method: The reverse genetics derived A/H5N1 virus strain (rgH5N1) was studied for adaptation to Vero cells by serial passage. It has been shown that the rgH5N1 strain can be propagated in Vero cells and cause CPE with the highest virus titer 1010,9 PFU/ml at Vero passage 15. The rgH5N1 strain was cloned by using plaque purification method and passaged to obtain a high stable virus titer. Conclusion: The reverse genetics derived A/H5N1 virus strain was propagated in Vero cells. Master seed virus and working seed virus were obtained at passage 6.