In addition, some of the failure of infectious coryza vaccination was due to the quality of vaccine and administration, and also some was due to the emergency of serotype B Haemophilus paragallinarum.

• 另外大多数鸡场的免疫失败是由于免疫效果不良所致，但也有相当一部分鸡场的免疫失败是由于B血清型的出现引起的。