[Evaluation on the biosafety of classical swine fever DNA vaccine]

The biosafety of DNA vaccine is one of the key questions which should be solved before it is used in the clinical trail. In order to evaluate the biosafety of DNA vaccine, the CSFV DNA vaccine was used in the studying target, two main aspects of the vaccine were explored in the study. Firstly, the possibility of integration of two kinds of DNA vaccine plasmids into pig genome was analyzed by PCR technology after the different vaccines were injected through the intramuscular introduction. The results showed that both plasmids DNA were detected as the form were not integrated into pig genome, it can be detected 30 copies plasmid DNA in 1 microg total genomic DNA as the sensibility of PCR, indicated the safety of the DNA vaccine. Afterward the environmental fecal and soil samples in the experimental pens were picked up. Then the antibiotic resistant bacteria were isolated and its resistant genes were analyzed by PCR and gene sequencing. The results demonstrated that the transfer and spreading of two DNA vaccine plasmids studied into environmental bacteria from receptor pigs were not found. The results showed that the CSFV DNA vaccine is safe to both pigs and the surrounding environment.