牛传染性鼻气管炎弱毒与牛病毒性腹泻弱毒抗原免疫干扰的研究

本试验使用3~6月龄健康易感牛9头(牛传染性鼻气管炎病毒(IBRV)和牛病毒性腹泻病毒(BVDV)抗原、抗体均阴性),共分3组,每组3头犊牛。第1组首免肌肉注射IBRV-LNM弱毒疫苗株种毒,接种1周后,每头牛接种BVDV-SM弱毒疫苗株;第2组只接种BVDV-SM弱毒疫苗株种毒,接种时间同第1组;第3组为对照组,接种MDBK细胞培养液。接种BVDV-SM疫苗毒后每周采血至疫苗毒接种后28 d,测定接种后BVDV抗体效价,并采用BVDV-JL检验用强毒进行攻毒试验。结果表明,第1组与第2组试验动物血清中牛病毒性腹泻病毒抗体水平无明显差异,能够抵抗BVDV-JL强毒攻击达到免疫保护的效果,说明牛传染性鼻气管炎病毒IBRV-LNM弱毒疫苗株接种后在牛体内对牛病毒性腹泻病毒BVDV-SM疫苗毒不产生免疫干扰作用。

Study on Immune Interference of Infectious Bovine Rhinotracheitis Virus and Bovine Viral Diarrhea Virus

This test using totle 9 head of cattles,which were 3 to 6 month old healthy and susceptible (IBRVand BVDV antigen negtive,antibody titer is less than or equal to 2),were divided into 3 groups,each group of 3 cows. The first group was injected with IBRV-LNM attenuated vaccine strain,one weeks later each animal was inoculated with BVDV-SM attenuated vaccine strain. The second group was only inoculated with BVDV-SM attenuated vaccine strain at the same time with the first group. The third group was the control group and inoculated with MDBK cell culture fluid. the determination of BVDV antibody titer post-vaccination every week until 28 days,and then challenged with BVDV-JL virulent strain. The results showed that the serum of bovine viral diarrhea virus antibody levels had no significant differences between the first and the second group, and observation after the challenge showed that the vaccine effectively protected calves from the challenge.This suggested that IBRV attenuated strain was not restrained BVDV attenuated vaccine virus in vivo.