中文摘要：

采用猪繁殖与呼吸综合征病毒（PRRSV）变异株HN07-01和经典美洲株BJ-4人工感染2月龄仔猪,通过观察发病情况、检测外周血免疫细胞和PRRSV特异血清抗体水平,研究了不同毒株PRRSV的致病特性。结果表明：PRRSV变异株感染后能够引起高热症状;变异株HN07-01株感染后引起的外周血各类免疫细胞下降速度和下降程度显著高于BJ-4株。提示PRRSV变异株引起机体的免疫抑制明显强于BJ-4株;PRRSV特异血清抗体结果表明：变异株和BJ-4株均能快速诱导机体产生抗体。

英文摘要：

In this study,2-month-old piglets were inoculated with porcine reproductive and respiratory syndrome virus（PRRSV） variant strain HN07-01 and classical strain BJ-4,respectively.To investigate the pathogenicity of different PRRSV strains,the clinical symptoms was observed and the peripheral blood immune cells and serum PRRSV-specific antibodies were detected.The results showed that the high fever was induced by PRRSV variant strain.Peripheral blood immune cells in HN07-01 infected piglets decreased significantly than that in BJ-4 strain,which indicated the severer immune suppression induced by PRRSV variant.The result of PRRSV-specific antibody detection showed that both the PRRSV variant and BJ-4 strain can induce antibody quickly.