为进一步研究高致病性猪繁殖与呼吸综合征(HP-PRRS)活疫苗(TJM-F92株)的安全性和免疫保护效果,本研究将HP-PRRS弱毒株TJM-F92与耐热保护剂混合制备疫苗,将该疫苗以每头猪2mL(10^6.4TCID50/mL)的剂量接种4周龄~5周龄仔猪进行安全性试验;并以每头猪1mL(10^5.0TCID50/mL)的剂量免疫仔猪28d后,利用同源强毒株(TJ株)攻毒进行保护效力检测。此外,分别采用10^3.5TCID50mL、10^4.0TCID50/mL、10^4.5TCID50/mL和10^5.0TCID50/mL的剂量,每头猪接种1mL,通过攻毒试验确定疫苗最小免疫剂量。结果表明:疫苗接种后,试验猪无不良反应,免疫组攻毒保护率为80%~100%,每头份疫苗病毒含量为10^4.5TCID50时对强毒攻击的保护率可达100%。本研究表明,该疫苗对猪安全,免疫保护效果良好,对HP-PRRS的防控将起到较大的推动作用。
To evaluate the safety and efficacy of the attenuated highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) vaccine strain of TJM-F92 derived from the HP-PRRS virus (HP-PRRSV) TJ strain, the lyophilized attenuated HP-PRRS vaccine was prepared with heat stable reagent, and the vaccine was inoculated into the 4-5 week old piglets for safety test at a dose of 2 mL (10^6.4 TCID50/mL) and for the protection test at a dose of 1 mL (10^5.0 TCID50), challenged with HP-PRRSV TJ strain at 28 days post vaccination. In addition, the minimum immunization dose (MID) was also determined in piglets inoculated with the vaccine at the dose of 10^3.5 TCID50, 10^4.0 TCID50, 10^4.5 TCID50, and 10^5.0 TCID50, respectively. The results revealed that the pigs inoculated with high dose of the vaccine (2×10^6.4 TCID50) did not show any clinical signs. Furthermore, the vaccine provided 80% to 100% protection to pigs against the HP-PRRSV challenging and the MID was 10^4.5 TCID50. These results indicated that the vaccine is safe, effective, and potential to be used for HP-PRRS prevention and control.