Abstract: To comparison the protective efficacy of inactivated porcine reproductive and respiratory syndrome virus（PRRSV）vaccines and commercial vaccines against highly pathogenic PRRSV（HP?PRRSV）challenge，twenty four ?weeks ? old piglets were selected from a PRRSV ?free pig farm. Piglets negative for all examined pathogens and antibodies against PRRSV and ASFV were selected for this study. Piglets were randomly divided into four groups（n= 5）and housed in separate rooms. Three groups of piglets were intramuscularly with（A，B and C），2 mL/pig. The piglets in the control group were inoculated with saline，2 mL/pig. All piglets were inoculated again by equal mannerand dose after three weeks. At 10 weeks of age，all pigs were challenged intranasally and intramuscularly with PRRSV XJL03（3×104.5 TCID50）in saline（1.5 ml，respectively）. Blood samples and nasal swab were collected at indicated times and rectal temperatures and deaths were recorded. All surviving piglets were necropsied at 21 days post ? challenge （dpc） for pathological examination. The result showed that four of five pigs of the control group （unvaccinated）were caused seven pathological lesions by HP?PRRSV challenge，three inactivated vaccines could not significantly relieved viremia and clinical symptom，vaccine A，vaccine B and vaccine C were provided only with 20% ，20% and 60% protection against piglets，respectively. In conclusion，our data suggest that the vaccine C vaccination protected 60% of piglets from challenging with HP?PRRSV strain and also provided comparable efficacy to that of the commercially licensed HP?PRRSV vaccine and Classical PRRSV vaccine.

Key words: Porcine reproductive and respiratory syndrome virus； Inactivated； Immune efficacy； Comparison

摘要： 该研究旨在评价自制猪繁殖与呼吸综合征全病毒灭活疫苗（XJL03株）与商品化疫苗 的免疫攻毒保护效果。选择4周龄仔猪20头，随机分为4组，每组5头猪，分别免疫三种全病 毒灭活疫苗（即疫苗A组、疫苗B组、疫苗C组），同时设置非免疫猪为对照组。各疫苗按照对应 的说明书进行免疫，3周后加强免疫1次。实验猪10周龄时，所有仔猪按照颈部肌肉注射和滴 鼻途径接种PRRSV?XJL03株，3×104.5 TCID50/头。攻毒后饲养观察21 d，在规定时间采集血液样 本和鼻拭子，并记录直肠温度和死亡情况。所有存活仔猪在攻毒后21天进行病理剖检。结果 表明，对照组猪4/5（未接种疫苗）发病，3种灭活疫苗不能显著减轻病毒血症和临床症状，疫苗 A、疫苗B和疫苗C对仔猪保护作用分别为20%（1/5）、20%（1/5）和60%（3/5）。实验表明，全病 毒灭活疫苗的保护效果有限，C疫苗能够保护60%仔猪免受高致病性猪繁殖与呼吸综合征病毒 的攻击，能够提供与商品化疫苗相当的保护效果。

关键词: 猪繁殖与呼吸综合征病毒； 灭活疫苗； 免疫效力； 对比