Advantages and problems of gene vaccine

Gene vaccine can not only produce humoral immune response, but also lead to the activation of cytotoxic T lymphocytes and induce cellular immunity. However, traditional vaccines can only induce cellular immunity with live vaccines, but there is a danger that the virulence of live vaccines will rise again.

Gene vaccine is to insert the gene encoding foreign antigen into the plasmid containing eukaryotic expression system, and then directly introduce the plasmid into human or animal body, so that it can express antigen protein in host cells and induce immune response. The continuous expression of antigen gene in a certain period of time constantly stimulates the immune system of the body and achieves the purpose of preventing diseases.

2. Existing problems

Plasmid DNA is usually not integrated into the genome of the host cell, and there is no evidence of insertion mutation at present. However, the possibility of mutation caused by inserting a few plasmid DNA into chromosomes cannot be completely ruled out. Once integrated into the genome, it may activate cytooncogenes or inactivate tumor suppressor genes.

The immune efficiency of gene vaccine is difficult to achieve 100% immune protection, and there are obvious species and individual differences, which may be related to different animal cells needing different promoters, antigen genes, administration methods and doses.

Extended data:

Genetic engineering vaccine is to isolate the protective antigen gene of pathogen by genetic engineering method or molecular cloning technology, transfer it into prokaryotic or eukaryotic system to express the protective antigen of pathogen, make vaccine, or delete the virulence-related gene of pathogen;

So as to become a gene deletion seedling of genes related to non-toxicity. ① polypeptide or subunit vaccine. ② particle carrier vaccine. ③ Virus live vector vaccine. ④ Bacterial live vector vaccine. ⑤ Gene recombination vaccines. ⑥ Gene deletion vaccine. For example, hepatitis B vaccine.

People's Network-Prevention and Treatment of Avian Influenza: Developing Genetic Vaccine is the Key