Consequently contamination of vaccine is likely if eggs used for vaccine production are derived from flocks infected with avian encephalomyelitis virus(AEV).

• 禽脑脊髓炎病毒可以经粪口水平传播,也可以通过鸡胚垂直传播,因此用感染了禽脑脊髓炎病毒的鸡群所产的鸡胚生产疫苗,就有可能使疫苗污染该病毒。