Comparison And Analysis Of Simultaneous And Separate Immunization Effects Of Sheeppox Vaccine And Peste Des Petits Ruminants Vaccine

Peste des petits ruminants(PPR)is a highly contagious acute viral disease.It is classified as a Class A severe infectious disease by the World Organization for Animal Health(OIE).Sheep pox(SP)is an acute,febrile,and contact infectious disease caused by the sheep pox virus,which causes serious harm to the growth of sheep.At present,some sheep farms choose to vaccinate the two vaccines at the same time to control the occurrence of diseases.However,the effect of combined immunization,the mutual interference between vaccines and the interference mechanism are still unclear.In this study,by detecting the changes in the level of antibodies produced in vivo after vaccinated animals,the level of virus replication and the changes in cytokines after the two vaccine viruses infect cells in vitro,the effects of immunity and the mechanism of interference between vaccines were preliminarily discussed.1.Analysis of the whole genome sequence of PPR vaccine virus and GTP vaccine virus.In this study,the vaccine virus was firstly passaged on cells stably.After the two stable vaccine viruses were harvested,the complete genome was obtained through sequencing,splicing,assembly,annotation,etc.,and then the whole genome sequence analysis was performed on it.The GTP vaccine strain measured in this experiment has high homology with the GTPV AV41(MH381810)strain,containing only 8 single nucleotide substitutions.Based on the analysis of the whole-genome phylogenetic tree,the PPR vaccine strain tested in this experiment is closely related to the Nigeria 75/1(KY628761 75/1)epidemic strain,with 99.9% homology.The GTP vaccine strain measured in this experiment has the closest genetic relationship with the GTPV AV41 vaccine strain,with a homology of 99.6%,and has a long evolutionary relationship with other isolates.Although the GTP vaccine strain measured in this experiment has the highest homology with the GTPV AV41 vaccine strain,there are still genomic mutations.Experimental results show that there is still a certain gap in the evolutionary relationship between domestic vaccine strains and domestic epidemic strains.2.The effect of mixed infection of PPR vaccine virus and GTP vaccine virus on goat fibroblast epithelial cells(GSF).In this study,the changes in the viral load and cytokine expression of PPR vaccine virus and GTP vaccine virus after mixed infection of GSF cells with PPR vaccine virus and GTP vaccine virus were detected,and the effects of mixed infection of PPR vaccine virus and GTP vaccine virus on cellular immune response were analyzed.influences.GSF cells were divided into PPRV and GTPV alone infection group;PPRV and GTPV co-infection group;PPRV and GTPV successively infected group;control group.The viral nucleic acid and total RNA of GSF cells were extracted 36 hours after virus inoculation,and real-time PCR was used to detect the changes in viral load and cytokine expression in each group.The results showed that GTPV infection showed characteristic lesions on cells;GTPV and PPRV co-infection inhibited PPRV replication;GTPV and PPRV co-infection promoted GTPV replication,and virus infection promoted TNF-α,IL-1β,and IL-6,IL-10,IFN-α,IFN-β mRNA expression of 2 to 170 times.3.Detection of antibody levels after sheep pox vaccine and Peste des ruminants vaccine simultaneously or separately immunized animals.In this study,95 healthy fattening sheep(2 months old)with negative PPR and SP antibodies,similar weights,and normal growth and reproduction were selected.All sheep were placed under the same conditions,and they were randomly divided into three groups for immunization.Blood was collected at 7,14,21,and 28 days after immunization and sent to the laboratory for antibody testing.The results showed that the antibody level of Peste des petits ruminants in the simultaneous immunization group was higher than that of the independent immunization group,and the antibody level of sheep pox in the simultaneous immunization group was lower than that of the independent immunization group.To sum up,the goat pox vaccine and the Pedestal Ruminant vaccine simultaneously immunize to promote the antibody level of the small anti;the goat pox vaccine and the Peste des ruminant vaccine simultaneously immunosuppress the antibody level of the goat pox,which indicates that the goat pox and the Pedestal ruminant vaccine are simultaneously immunized It is not conducive to the sheep pox vaccine to produce a better immune response in the body.In vitro mixed infection of goat pox and Peste des ruminants vaccine virus inhibits the replication of the Peste des petits ruminants vaccine virus and at the same time inhibits the replication of the goat pox vaccine virus.The analysis of the whole genome sequence of PPR vaccine virus and GTP vaccine virus shows that there is a certain gap in the evolutionary relationship between domestic vaccine strains and domestic epidemic strains.This study provides theoretical guidance for the immunization program of sheep farms.