Nucleic acid and recombinant protein co-immune vaccine based on classical swine fever virus gene as well as preparation method and application of co-immune vaccine

Abstract

The invention discloses a nucleic acid and recombinant protein co-immune vaccine based on a classical swine fever virus gene as well as a preparation method and application of the co-immune vaccine. The preparation method comprises the steps that firstly, optimized recombinant plasmids and recombinant classical swine fever vaccine antigen protein are obtained by combining gene engineering and cellengineering; then the nucleic acid sequence and the recombinant protein are compounded into different liquid phase layers of a biphasic adjuvant, so that the obtained co-immune vaccine is good in immunogenicity and short in immune blank period, can rapidly induce an organism to generate high-level, high-affinity and durable antibody response and immune memory, effectively protects a target animalfrom being attacked by classical swine fever virulent viruses, and the method can be applied to preparation of products for preventing/treating classical swine fever.

Description

technical field [0001] The invention relates to the technical field of vaccine preparation, in particular to a nucleic acid and recombinant protein co-immunization vaccine based on classical swine fever virus gene, a preparation method and application thereof. Background technique [0002] Classical swine fever (CSF) is caused by classical swine fever virus (CSFV), mainly attacks domestic pigs and wild boars, and can cause severe zoonotic diseases with high morbidity and mortality. The World Organization for Animal Health (OIE) "World Animal Health Code" lists it as a Class A epidemic disease, and my country's "Regulations for the Implementation of Livestock and Poultry Epidemic Prevention Regulations" stipulates it as a class I animal infectious disease. Because of its serious harm and wide distribution, it has become one of the hot spots in the research of molecular virology and veterinary epidemic prevention at home and abroad. [0003] CSFV is a member of the Flavivirid...

AI Technical Summary

Problems solved by technology

[0005] Since 1950, my country has used live swine fever vaccine (rabbitized attenuated strain, referred to as HCLV strain or C strain) for large-scale immunization to control the large-scale epidemic of swine fever. The characteristics of rapid, high morbidity and mortality have transformed into mild onset, atypical symptoms, low morbidity and mortality, and the characteristics of regional, sporadic and periodic epidemics, especially due to latent infection and immune tolerance. The chronic and atypical swine fever caused by it is an important form of clinical manifestations of swine fever in my country at present, causing extremely serious harm to the healthy development of the pig industry

[0006] Studies have shown that under the high pressure of the C-strain live vaccine, the CSF virus is escaping and mutating in the direction opposite to the vaccine's protective effect. The protection effect is not ideal

[0007] In addition, commercially available live CSF vaccines such as splenocyte vaccines, bovine testicular cell vaccines, ST passage cell vaccines, etc. also have the following disadvantages: (1) the production process is easily contaminated by exogenous viruses such as BVDV; (2) live rabbits infected with The method of measuring the infection amount of rabbits is to titrate the virus content. The test method is unscientific and affected by the individual differences of the rabbits used for testing, resulting in large differences between batches of vaccines and unstable quality; The use process has very strict temperature requirements, and the titer is easy to decrease, which affects the immune effect; it is greatly interfered by maternal antibodies, and has low protection for nursery pigs; it is easy to produce immune tolerance and affect herd immunity; it cannot be used for wild virus-infected pigs. Differential diagnosis increases the difficulty of swine fever purification

However, the duration of immunity of current nucleic acid vaccines is short and the immune response is weak, which greatly limits the commercial application and promotion of this technology, and further improvement is urgently needed

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