新城疫热稳定性天然弱毒株B95免疫效果的研究

分别用ＮＤＶ疫苗株和不同稀释度的Ｂ９５Ｇ毒株，经不同免疫途径进行雏鸡的免疫，当雏鸡ＮＤＶ母液抗体下降到较低水平时，Ｂ９５病毒液５０倍稀释组在免疫后５d即可见抗体滴度上升，到达高峰时抗体效经免疫前上升４．６个滴度，在攻毒试验中，除Ｂ９５１００００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50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，能使机体产生良好的免疫。

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

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.