A proventriculus-type of avian infectious bronchitis virus was isolated from diseased fowls in China, and designated as strain IBV - D971. After 120 passages on SPF chicken embryos, an attenuated vaccine was developed and designated as strain IBV-D971P.

• 从国内发病鸡群中分离到鸡传染性支气管炎(嗜腺胃型)病毒(IBV-D971株).；在SPF鸡胚上连续传至120代