新城疫热稳定性天然弱毒株B95免疫效果的研究

Preliminary study on the immunological characteristics of newcastle disease virus strain B95 naturally avirulent and heat stable strain

分别用NDV疫苗株和不同稀释度的B95毒株 ,经不同免疫途径进行雏鸡的免疫 ,当雏鸡NDV母源抗体下降到较低水平时 ,B95病毒液 5 0倍稀释组在免疫后 5d即可见抗体滴度上升 ,到达高峰时抗体效价比免疫前上升 4.6个滴度 ,在攻毒试验中 ,除B95 10 0 0 0倍稀释组外 ,其余B95各组在免疫后 15d、30d攻毒保护率均为 5 / 5 ,即全部保护。当在雏鸡母源抗体较高时免疫 ,B95病毒液 5 0倍稀释组抗体达高峰时其效价比对照组高 2 .5个滴度 ,结果表明 ,该组与Clone30疫苗组免疫效果相当 。

Chicken were immunized with different Newcastle disease virus (NDV)vaccines or with B95 strain in different dilutions or by different immunization methods. When containing a low level of maternal NDV antibody,chicken immunized with B95 strain in a dilution of 50 times could be observed a increasing in HI titre 5 days after immunization, and with a highest level of 4.6 titre higher than control group. In challenge experiment, each B95 group except in a dilution of 10 000 times could be protected completely 15 or 30 days after immunization. If chicken were immunized at a high maternal level, HI antibody titre of the B95 group in a dilution of 50 times was 2.5 higher than control group,which was similar with Clone30 group.