Then, detected by ELISA in serum specific IgG, intestinal lavage fluid sIgA antibodies, spleen lymphocyte proliferation activity levels and CD4+, CD8+ T lymphocyte typing ratio; and evaluated by animal challenge protection test their immunity. 采用ELISA法分别检测血清中特异性IgG、肠灌洗液中sIgA抗体、脾脏淋巴细胞增殖活性水平及CD4+、CD8+T淋巴细胞分型比值;并通过动物攻毒保护试验对其免疫效果进行评价。