关键词: 猪繁殖与呼吸综合征病毒； 灭活疫苗； 免疫效力； 对比

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