Study Of Safety Evaluation Of Vaccine Of Recombinant Vaccinia Virus With Japanese Encephalitis Virus

Over the past few years, Japanese encephalitis virus (JEV) spread widely in ourcountry and even in Asia, threatening the safety of people and livestock. With theefforts of the Chinese government and relevant departments, the morbidity andmortality of people suffering from Japanese encephalitis declined gradually. But thereis no Japanese encephalitis virus vaccine for pig to prevent Japanese encephalitis virus.Currently the attenuated vaccine SA14-14-2is used generally for immunization ofpigs. Therefore, according to the current situation of China’s pig industry, a dedicatedsafe and effective Japanese encephalitis virus vaccine for swine is needed. Therecombinant vaccinia virus vaccine rVTT-JEVE with E antigen gene of Japaneseencephalitis virus developed in our laboratory has good immune effect, but the safetyof the vaccine has not been proven.In this study, we evaluated the safety of the recombinant vaccinia virus vaccinerVTT-JEVE developed by our laboratory. In the first place, we studied the physicaland chemical properties of recombinant vaccinia virus rVTT-JEVE treated bytemperature, pH, ether, trypsin, chloroform, ultrasonic and ultraviolet with differentvariables and appropriate physical and chemical factors. And then we detected thechanges of viral titer after those treatments. The results showed that it was sensitive toheat, chloroform, trypsin and ultrasound, and had a certain tolerance to acid and alkali,and there was a certain degree of sensitivity to ultraviolet light. We completed a studyon the physical and chemical characteristics.To begin with, we uesd mice to do relative research, and preliminarily evaluatedthe safety of recombinant vaccinia virus vaccine rVTT-JEVE, The level of specificantibodies produced after immunifaction in mice was significantly higher than theattenuated vaccine group and the control group (P <0.05). We detected residues ofrecombinant vaccinia virus in mice by means of RT-qPCR. The results showed thatthe copies of the recombinant vaccinia virus in micer were significantly reduced after5-7d. And we analysed the humoral immune and viral residues, the results indicatedthat the candidate vaccine has a good humoral immune and the viral residue in micewas just5-7d. We immunifacted pigs and analyzed immunological properties and viral residue and the environment release. The final results showed that therecombinant vaccinia virus candidate vaccine rVTT-JEVE had good immunogenicity,and the viral residue in pigs was just3days, and the recombinant vaccinia virus willnot release in the environment, indicating that the candidate vaccine had good safety.