山羊痘弱毒疫苗(AV41株)接种途径和剂量对牛抗体反应的影响

Effects of inoculation routes and doses of attenuated goat pox vaccine(AV41 strain)on antibody response in cattle

为评估山羊痘弱毒疫苗(AV41株)经皮下和皮内接种牛体后的抗体产生规律,优化牛体免疫程序,选取25头健康成年肉牛分为5组,每组5头,标准单头份剂量为含量1.0×10^(3.5)TCID_(50) AV41株,分别以5倍和10倍羊用剂量进行皮下和皮内免疫,于接种后0、15、30、45和60 d,利用病毒中和试验(VNT)和ELISA试剂盒检测血清抗体水平。结果显示:鼻咽拭子和血液PCR结果均为阴性,未出现排毒;VNT与ELISA抗体检测结果相似,免疫后第30天,皮下接种5倍剂量组中有60%牛抗体转阳,中和抗体滴度最高达1∶640。同时,皮内和皮下10倍剂量组各有40%牛抗体转阳,皮内5倍剂量组有20%牛抗体转阳。VNT中和指数与ELISA的S/P值呈现显著正相关。上述结果表明,类似于国际上相关疫苗的接种途径和剂量,皮下注射5倍羊头份剂量山羊痘弱毒疫苗是安全和有效的,可作为临床预防牛结节皮肤病的免疫接种方案。

To evaluate the dynamics of antibodies production after subcutaneous and intradermal inoc⁃ulation of attenuated goat pox vaccine(AV41 strain)in cattle and optimize the immunization program of cattle,25 healthy beef cattle were randomly assigned into 5 groups and inoculated subcutaneously and intra⁃dermally at 5 and 10 times of goat dose,respectively.The standard single dose was 1.0×10^(3.5) TCID_(50) AV41 strain.At 0,15,30,45 and 60 days post vaccination,the serum antibody level was detected by both virus neutralisation test(VNT)and a commercial ELISA kit.The PCR results of nasopharyngeal swabs and blood were negative without shedding vaccine strain.The results of VNT and ELISA antibody detec⁃tion were similar,60%of the cattle in the subcutaneous inoculation with 5 times dose group seroconverted on day 30 post vaccination,with the maximum neuralising antibody titer of 1∶640,followed by the intrader⁃mal inoculation with 10 times dose group and subcutaneous inoculation with 10 times dose group(40%),while only 20%seroconverted in the intradermal inoculation with 5 times dose group.The neutralisation in⁃dex of VNT was significantly positively correlated with the S/P value of ELISA.The above results suggest that similar to the inoculation route and dose of relevant international vaccines,subcutaneous inoculation of AV41 at a 5 times goat dose is safe and effective and can be used as a clinical vaccination protocol for lumpy skin disease.