Pseudorabies virus passage attenuated strain and application thereof

Abstract

The invention provides a pseudorabies virus passage attenuated strain and an application thereof, and belongs to the field of vaccines of animal medicine. The pseudorabies virus passage attenuated strain is a pseudorabies virus LA2017 strain, and the preservation number is CGMCC No.18170. The invention also provides an application of the pseudorabies virus passage attenuated strain to preparationof pseudorabies vaccines, and a vaccine using the pseudorabies virus passage attenuated strain as an active component. The LA2017 strain is a natural deletion attenuated strain, the virulence is notably reduced, and when new-born piggies are inoculated with the LA2017 strain, no adverse reactions are caused. The strain is obtained by a passage attenuated method, so that the biological security risk is low. After weaned highly-susceptible piggies are subjected to primary inoculation of the vaccines prepared from the LA2017 strain for 7 days, 100% of protective effects can be achieved, and the immunization persistent period can achieve 5 months. The vaccines not only can prevent pathogenesis but also can prevent toxin expelling, and purification of pseudorabies virus variation strains can beextremely facilitated.

Description

technical field [0001] The invention belongs to the field of vaccines in animal medicine, and in particular relates to a pseudorabies virus passaging attenuated strain and application thereof. Background technique [0002] Pseudorabies is a common disease that occurs in many animals, and its pathogen is pseudorabies virus (Pseudorabies Virus, PRV). Domestic animals (including cattle, sheep, etc.), wild animals (including foxes and minks, etc.) Typical neurological symptoms. Pigs are the storage host of pseudorabies virus. Piglets usually have a high mortality rate after onset, while large pigs generally do not die, but they can be infected and carry and shed the virus for a long time. Pigs with different ages have different clinical characteristics of pseudorabies. Abortion often occurs in sows; newborn piglets have neurological symptoms and high mortality; fattening pigs mainly have respiratory symptoms, and adult pigs grow stagnant after being infected with pseudorabies ...

AI Technical Summary

Problems solved by technology

[0003] However, since 2011, a mutated PRV wild strain has re-emerged in many pig farms in my country. The virulence of this mutant strain is significantly enhanced compared with the traditional strain, and it can cause 100% death to pigs over 9 weeks old. Although the original vaccine can provide certain protection, its protective effect is seriously insufficient and cannot prevent the onset and shedding of the virus. Studies have shown that its main antigen genes gB, gC and gD have obvious mutations with traditional vaccine strains. In order to better prevent and control PRV mutations The harm of strains to pigs, the use of mutant strains to develop homologous vaccines is the key to the prevention and control of porcine pseudorabies in my country. The development of new vaccines for mutant strains usually uses methods such as artificial gene deletion or passage weakening. When the artificial gene is missing, if There are fewer deleted genes, there may be high residual toxicity, and the safety is not high enough

For example, the invention patent with the application number 201510388390.9 discloses that the LA-A strain obtained by artificially deleting the gE gene of the pseudorabies virus wild virus AH02LA strain is only safe for 4-week-old piglets, but it is still highly pathogenic to newborn piglets

When the artificial gene is deleted, if there are many missing genes, it may affect the cultivation and immune efficacy of the virus, and the artificial gene deletion has biosafety risks, and the safety evaluation of agricultural genetically modified organisms must be carried out, and it can be used only after passing the test

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