豚鼠动物模型评价牛口蹄疫Asia-1型灭活疫苗效力的研究

Evaluation on the potency of inactivated vaccine against foot-and-mouth disease virus Asia 1 from cattle using guinea pigs as animal model

以豚鼠为试验动物模型,探索一种应用豚鼠替代牛进行牛口蹄疫Asia-1型灭活疫苗效力检验的方法。豚鼠和牛同步对6批牛口蹄疫Asia-1型灭活疫苗进行PD50效力检验,其中2批进行重复性试验。豚鼠分别在免疫后7、14、21和28天采血检测Asia-1型的中和抗体水平。统计学分析显示,测定的豚鼠PD50和牛PD50之间具有极显著的相关性(R=0.846,P<0.01);经回归分析,建立了应用豚鼠测定的PD50预测牛口蹄疫Asia-1型灭活疫苗效力的线性回归模型(y=1.625x-0.704;x表示豚鼠PD50结果;y表示牛PD50结果)。F检验(F=15.058,P=0.008)和t检验(t=3.880,P=0.008)证明该线性方程成立。豚鼠的Asia-1型抗体水平随免疫剂量的增加而升高,攻毒时的抗体水平与攻毒后的保护力存在正相关关系。本研究初步证明,在未来的效力检验中豚鼠可作为试验动物替代牛进行口蹄疫Asia-1型灭活疫苗效力检验。

Guinea pig was used as an animal model to evaluate the potency of inactivated vaccine against foot-and-mouth disease virus （FMDV） Asia 1 from cattle. Six batches of inactivated vaccines were tested for their 50% protective dose （PDso） using guinea pigs and cat- tie at the same time. Among the six batches, two batches were repeatedly tested. Guinea pigs were bled at days 7, 14, 21 and 28 post-vacci- nation, serum samples were used to determine the virus neutralizing antibody titers against serotype Asia-1 FMDV. Statistical analysis of the results demonstrated a very significant correlation of PDs0 value of inactivated bovine serotype Asia-1 FMD vaccines between tests in guinea pigs and in cattle （ R=0. 846, P〈0. 01 ）. A linear regression model y1. 625x-0. 704, where x is PD50 in guinea pigs and y is PD50 in cattle, was created for the prediction of potency of inactivated bovine serotype Aaia-1 FMD vaccines using PDs0 value obtained in guinea pigs. Furthermore, the model was strongly supported and approved by F test （F = 15. 058, P= 0. 008） and T test （t = 3. 880, P = 0. 008 ）. Anti- body titers against serotype Aisa-1 FMDV in inoculated guinea pigs increased as the increasing of immunizing dose. There was a positive cor- relation between antibody titers in guinea pigs at challenge and the protection of the guinea pigs from the FMDV challenge. This initial study revealed that guinea pig can be used to replace cattle as the laboratory animal for the needed potency tests of inactivated bovine serotype Asia-1 FMD vaccines in future.