| serological studies of infectious bronchitis vaccines against japanese field isolates of homologous and heterologous genotypes. | the genetic diversity of the partial s1 gene involving the hyper variable region for infectious bronchitis (ib) vaccine strains in japan were compared with those of ib virus isolated from the field in japan. field isolates have mainly been classified into three major genotypes, jp-i, jp-ii and jp-iii, since 2003; however, the 4/91 genotype was detected from recent field isolates in japan. the virus neutralization (vn) activity with vaccine immunized serum was investigated to evaluate the protect ... | 2009 | 19652475 |