牛传染性鼻气管炎弱毒疫苗免疫抗体水平与保护效力的关系

Study on relationship between the level of immunity antibody and the attack protection of live attenuated infectious bovine rhinotracheitis vaccine

利用微量血清中和试验和攻毒试验、牛传染性鼻气管炎弱毒活疫苗检测免疫后牛血清中牛传染性鼻气管炎病毒的抗体效价及其与保护效力的平衡关系。40头牛其中弱毒活疫苗免疫牛30头,对照牛(抗体阴性牛)10头,采用不同剂量免疫(10^(3.5)～10^(6.5)TCID_(50)/mL),按抗体效价高低将实验动物分,并用IBRV LN01/08强毒株攻击,将攻毒保护结果与攻毒时抗体效价结果平行比较分析,结果显示,当IBRV抗体效价高于1:6时,疫苗免疫可以对牛产生良好的保护效力,保护率在80%以上,低于1:6但高于1:3时,免疫苗抗体阳性牛攻毒后保护率近78%。试验结果显示牛传染性鼻气管炎活疫苗的抗体水平于保护效力之间存在一定的平行关系。

Tested the titer of IBRV antibody in the immuned bovine serum with micro--serum neutralization method. Evaluated the parallel relationship in the protective effect of the infectious bovine rhinotracheitis attenuated live vaccine with the serum neutralization test and attack test. In the test, 30 tattles were immuned with the attenuated live vaccine using different doses （10^3.5 - 10^6. 5 TCID50/mL） , 10 tattles bovine （the antibody of the IBRV was negative） were considered as control, experiment animals were divided into four groups according to the titer of IBRV antibody （group 1：1 ： 3〈SN≤1 ： 6, 9 cattles; group 2：1 ： 6 〈 SN≤1 ： 16, 12 cattles; group3：1 ： 16〈 SN≤1 ： 64, 9 cattles; group 4： control group, 10 cattles）, then all the cattles were attacked with IBRV LN01 / 08 virulent strain with the doses of 107.0 TCID50/4 mL. The percentage of the protective effect： group 1： 7/9; group 2： 1/ 12; group 3： 8/9; group 4：0/10. At last, we made a parallel comparative analysis between the attack protection and the anti body titer when were attacked, the results showed that when the IBRV antibody titer was higher than 1 ： 6, the vaccine can provided effect protection, the rate of which was more than 80% ; when the IBRV antibody titer was between the 1 ： 3 and 1 ： 6, the rate of protection was nearly 78%. The results showed that there existed parallel relation between the antibody levels of the infectious bovine rhinotracheitis vaccine and the protective efficacy.