VP 2 cDNA gene of the infectious bursal disease virus HZ96 strain, encoding a major host protective antigen, was cloned into baculovirus transfer vector pBacPAK8, resulting in a recombinant transfer vector pBacPAK VP 2. The vector pBacPAK VP 2 and linearized DNA of modified baculovirus Bm BacPAK6 were co transfected into the cultured Bombyx mori (Bm) N cells, in which homologous recombination occurred. Then, baculovirus recombinants were screened out. The Bm cells and Bm larvae were infected...