Some evidence of the immunoprotectivity was a found in the 3 groups at 7DPC by showing less prominent antibody increase, body weight drop and BBR drop.

• 于攻毒后7日抗体跳升、体重下降和BBR下降情形，也以上述三免疫组较不明显，显见疫苗之免疫已受到保护。