| abstract |
The invention contains an infectious bursitis virus having both a characteristic of reducing the size of the bursitis, defined as a bursitis / weight ratio, when administered to chickens to less than 55% and the ability to protect poultry with an ELISA antibody titer of at least about 500. A vaccine capable of protecting poultry from infectious bursitis infection, characterized in that; And to viruses having the above characteristics.n n n Infectious bursitis virus, poultry, ELISA antibody titer, vaccine, toxic virus |