Safety and efficacy of recombinant pseudorabies virus (rPRV-GP5) against pseudorabies in sheep

To test the safety and efficacy of the recombinant pseudorabies virus (PRV) expressing porcine reproductive and respiratory syndrome virus (PRRSV) GP5 (rPRV-GP5) developed earlier against pseudorabies,Ten 5～ 6-month-old sheep were randomly divided into three groups,one group of 4 sheep (efficacy group) were immunized intramuscularly 10~(6.0) PFU,one group of 3 sheep (safety group) were immunized intramuscularly 10~(6.0) PFU,and the third group of 3 sheep were served as control group.Fourteen days post-immunization,animals in efficacy and control groups were challenged by intramuscular inoculation with 10~3 LD50 of the highly virulent PRV S strain of porcine origin.The results showed that vaccinated sheep were protected from lethal challenge of PRV,and rPRV-GP5 represents a candidate vaccine against porcine pseudorabies.