| 摘要 |
PURPOSE: Provided is a broad spectrum IBDV vaccine that is able to induce a protective immune response against classical- and variant E IBDV strains. Moreover, the vaccine can be administered to poultry by mass application routes. CONSTITUTION: The IBDV mutant comprises the nucleotide sequences encoding a variant E VP2 protein in segment A of the viral genome and is able to infect and replicate in CEF tissue culture. It is characterized in that the mutant comprises one or more mutations in the variant E VP2 coding region such that, (i) the codon for the amino acid at position 254 encodes Glycine, and/or (ii) the codon for the amino acid at position 270 encodes Threonine. Wherein, the codon for amino acid 254 is GGC and/or the codon for amino acid 270 is ACG; and the coding region for the 253-284 fragment of the variant E VP2 protein is replaced by the corresponding coding region of D78 strain of IBDV.
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