In order to evaluate the immunogenicity of a candidate reassortant bivalent attenuated bovine rotavirus (BRV)vaccine (strains LLR-85 and R191),the cows pregnant for 7 to 8 months were immunized with the bivalent attenuated vaccine which was combined with LLR-85 (G10) and R191 (G6) strains in equal proportions and emulsified with adjuvant.The IgG,IgA and viral neutralizing (VN) antibodies against BRV in bovine serum were detected by using indirect ELISA and VN test.The results showed that the highest titers of the serum antibodies were induced in all inoculated cows at 2 weeks post immunization,and the antibody titers were up to 4 to 32 times of the original antibody titer,which lasted about 2 months.In addition,the vaccine had no side effects on the pregnant cows,such as abortion and other clinical reactions.Moreover,calves acquired the highest levels of serum and intestinal mucosal antibodies after birth by feeding the colostrum.The results suggested that the bivalent attenuated vaccine was safe for the pregnant cows and able to efficiently induce specific antibodies for protecting of calf through the colostrum.These results provided experimental basis for the clinical application of the bivalent attenuated reassortant BRV vaccine (LLR-85 and R191).%为评价牛轮状病毒(BRV)基因重组二价减毒疫苗(LLR-85和R191株)对怀孕母牛的免疫反应,本研究将RV LLR-85(G10)和R191(G6)株等比例混合后进行乳化,肌肉途径接种怀孕7个～8个月的母牛.采用间接ELISA和病毒中和(VN)试验对接种牛血清抗BRV的IgG、IgA以及VN抗体进行检测.结果显示,接种2周后抗体水平达到峰值,可以使原有的抗体滴度升高4倍～32倍,高滴度抗体可持续约2个月,接种母牛均未发生流产等副反应.犊牛通过饲喂初乳,可以在出生后1d内获得最高水平的血清和肠道粘膜抗体.结果表明,BRV基因重组二价减毒疫苗对孕牛不但具有良好的安全性、而且其高滴度抗体可以通过初乳使新生犊牛获得有效的被动免疫.这些研究结果为该疫苗的临床应用提供了实验依据.
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