|Rapid development witnessed in livestock & poultry vaccine technology system|
Supported by the 863 Program of MOST and aiming to promote immunological competence and safety of genetic engineering vaccines, China's livestock & poultry genetic engineering vaccines and immunological adjuvant technology system witnessed significant progress. Based on the cloning of the related genes used in the antigen or vaccine research and development activities, a stable carrier with a highly efficient expression has been constructed and the safety assessment system and scale production technology for genetic engineering vaccines have been put in place and further improved.
In addition to successful development of the bivalent genetic engineering vaccine for the avian infectious bursal disease (IBD), 4 types of DNA vaccines (such as the nucleic acid vaccine for porcine reproductive and respiratory syndrome), the genetic engineering lactobacillus vaccine for rotavirus and the vaccines for avian infectious coryza, a production technology has been constructed and improved for the Min Gene Strain A SA215 three-gene-deleted vaccine for the porcine pseudorabies virus and a complete set of research data has been obtained for the application of the national certificate of new veterinary medicines for SA215 live vaccine for the porcine pseudorabies virus.
All the documentation and data required for the application of new veterinary medicine certificate have been made available for TK-/gG-two-gene-deleted proviral vaccine, TK-/gE-/gI-gene-deleted proviral vaccine and gG-gene-deleted inactivated oil emulsion vaccine for porcine pseudorabies virus, with the TK-/gG-bi-gene-deleted proviral vaccine for porcine pseudorabies virus successfully obtained the national certificate of new veterinary medicine. rH5N3, a high-yield and recombinant avian influenza vaccine strain with molecular labeling, has been constructed, which is 100% protective to the H5N1 sub-type highly pathogenic avian influenza (HPAI) on chicken and ducks and other water birds and eliminated the shortcomings of the avian influenza vaccines currently in use, such as poor antigenicity, uncertain immunological effect on water birds, etc. Experimental researches reveal that DNA vaccines have achieved a protective rate of more than 90% for counteracting toxic substances while the rotavirus genetic engineering lactobacillus vaccine has had an immunoprotection rate of more than 80% with a period of immunity of more than 1 year.
In the meanwhile, significant progress has also been made in the R&D of new and highly efficient avian immunological adjuvant, which will become a major driver in promoting the immunological effect of vaccines for animals. CpG, IL-6 and IL-15 molecular immunological adjuvant are prepared and a technology platform with immunological activity and abundant recombinant plasmid with different lengths and different motif has been built. As the recombinant plasmid realizes mass production, the antibody level of avian influenza inactivated vaccine will be promoted by 2 to 4 times. A massive extraction and purification technology using the improved alkali lysis method for 150L genetic engineering bacteria with abundant CpG recombinant plasmid has been established and recombinant plasmid of high purity has been obtained. In addition, break-through development has also been achieved in the cloning and expression of cytokine gene and coccidium antigen gene with the successful cloning of IL-15, IL-17 and IL-18 avian interleukin and lymphocyte chemokines gene.