Primary Study of the Biological Charateristics of Pseudorabies Virus Gene-Deleted Vaccine Strain

On the basis of construction the transfer vector pgEI-GFP of Pseudorabies virus SH strain BHK-21, which was infected with PRV-SH for 1-2h, were tansfected with the complex of pgEI-GFP and DOTAPA deletion mutant was selected and purified 3-4 times in BHK-21 cell through GFP. In the research here, we investigated the gE-/gI-/GFP+ PRV vaccine strain growth properties in cultured cells, its safety for rabbits, its LD50 for mice, its safety and immunity for postweaning piglets, and its biological properties. The results suggested that gE and gI genes deletion may not affect PRV’s propagation in cultured cells, nor the typical PRV plaque forming. The investigated results demonstrated that the virulence of gE-/gI-/GFP+ was reduced when compared with that of PRV-SH. The inoculation of gE-/gI-/GFP+ couldn’t harm the post-weaning pigs, couldn’t induce the viral spread in surroundings. The period of fever and the number of days of existing virus in treated group pigs were less than that in the control group after big dose of RPV-SH were used to equally attack the treated and control group pigs through ear veins 5 weeks later. gE-/gI-/GFP+could always induce the high titer PRV neutralizing antibodies throughout the experiment.