嵌合型猪圆环病毒PCV1-2及PCV2 ORF2真核表达质粒对商品猪的免疫保护研究

chimeric virus PCV1-2 live virus and eukaryotic expression vector pcDNA3.1/V5-His-orf2 were vaccinated in commercial pigs with maternal antibody titers determined by ELISA varied from 0.07 to 0.60. A total of 9 pigs were randomly assigned to four groups. Pigs in group 1 were vaccinated by intramuscular injection with 10 3.5 50% tissue culture infective doses (TCID50) of the chimeric PCV1-2 live virus. Pigs in group 2 were vaccinated by intramuscular injection with 200µg of recombinant plasmid. Pigs in group 3 were vaccinated by intramuscular injection with 200µg of pcDNA3.1. Pigs in group 4 were served as challenge control. By 42 days postvaccination (DPV), pigs in group 1 and group 2 had seroconverted to PCV2 capsid antibody. At 42 DPV, all pigs were challenged intramuscularly with 2×104.5TCID50 of pathogenic PCV2 virus and 106TCID50 of PRRSV virus. Necropsies were performed at 21 days post-challenge, the lymph nodes in the nonvaccinated but challenged pigs were larger than those of vaccinated pigs. The PCV2 genomic copy loads in lymph nodes were reduced in vaccinated pigs. Moderate amounts of PCV2 antigen were detected in most lymphoid tissues of nonvaccinated pigs. These data indicated that when given intramuscularly in pigs, the chimeric PCV1-2 live virus and recombinant plasmid induces protective immunity against PCV2 infection and could potentially serve as an effective vaccine.