This study compared the efficacy, in terms of reproductive performance, of a porcine reproductive and respiratory syndrome virus (PRRSV)-1 or PRRSV-2 modified-live virus (MLV) vaccine against a dual heterologous PRRSV-1 and PRRSV-2 challenge. Gilts were administered either the PRRSV-1 or PRRSV-2 MLV vaccine at 21 days prior to breeding and were challenged intranasally with both PRRSV species at day 93 of gestation. Vaccination of gilts with PRRSV-2 MLV vaccine resulted in improved reproductive performance in sows (e.g. duration of pregnancy) and piglet health and overall viability (e.g. increase of the number of live-born and weaned pigs, and decrease of stillborn). Vaccination of gilts with PRRSV-1 MLV vaccine was able to reduce only PRRSV-1 viremia in contrast, PRRSV-2 MLV vaccine was able to reduce both PRRSV-1 and PRRSV-2 viremia. Vaccination of gilts with PRRSV-2 MLV induced higher numbers of PRRSV-2 specific interferon-γ secreting cells (IFN-γ-SC) compared to the PRRSV-1 MLV while there was no difference in the number of PRRSV-1 specific IFN-γ-SC between the two vaccines. Taken together, the results presented here suggest that vaccination of gilts with the PRRSV-2 MLV vaccine is more efficacious against dual heterologous PRRSV-1 and PRRSV-2 challenge compared to the PRRSV-1 MLV vaccine.

中文翻译：

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比较商业改良活体PRRSV-1和PRRSV-2疫苗与晚期妊娠母猪双重异源PRRSV-1和PRRSV-2攻击的比较。

这项研究就繁殖性能而言，比较了猪繁殖与呼吸综合症病毒（PRRSV）-1或PRRSV-2改良活病毒（MLV）疫苗对异源PRRSV-1和PRRSV-2双重攻击的功效。在繁殖前21天，给小母猪接种PRRSV-1或PRRSV-2 MLV疫苗，并在妊娠第93天对两种PRRSV物种进行鼻内攻击。用PRRSV-2 MLV疫苗接种后备母猪可以改善母猪的生殖性能（例如妊娠持续时间），改善仔猪的健康状况和总体生存能力（例如，增加活产和断奶猪的数量，减少死胎）。相比之下，用PRRSV-1 MLV疫苗接种后备母猪只能减少PRRSV-1病毒血症，PRRSV-2 MLV疫苗既可以减少PRRSV-1和PRRSV-2病毒血症。与PRRSV-1 MLV相比，用PRRSV-2 MLV接种后备母猪诱导的PRRSV-2特异性干扰素-γ分泌细胞（IFN-γ-SC）数量更多，而PRRSV-1特异性IFN-γ的数量没有差异两种疫苗之间的γ-SC。综上所述，此处提出的结果表明，与PRRSV-1 MLV疫苗相比，PRRSV-2 MLV疫苗对小母猪的疫苗接种对双重异源PRRSV-1和PRRSV-2攻击更为有效。