Preparation method and application of attenuated live vaccine chitosan microsphere for porcine epidemic diarrhea virus

Abstract

The invention discloses a preparation method and application of attenuated live vaccine chitosan microsphere for a porcine epidemic diarrhea virus. The method comprises the following steps: culturinga porcine epidemic diarrhea virus attenuated strain PEDV-YN144, and filtering, so as to obtain virus filtrate; adding a sodium hydrogen carbonate solution into the virus filtrate, slowly dropwide adding a chitosan solution under a magnetic stirring condition; slowly dropwise adding a sodium tripolyphosphate solution; and stirring, so as to obtain mixed liquid; uniformly mixing gelatin with the mixed liquid, and carrying out freeze drying, so as to obtain the attenuated live vaccine chitosan microsphere for the porcine epidemic diarrhea virus. An organic reagent is not added in a packaging process adopted in the method, the antigen activity is preserved, the preparation process is simple, the time is saved, and the attenuated live vaccine chitosan microsphere is easy to store and transport.According to the attenuated live vaccine chitosan microsphere for the porcine epidemic diarrhea virus, the immune effect of a vaccine can be improved, and the action time of the vaccine can be prolonged.

Description

technical field [0001] The invention relates to the field of biomedicine, in particular to a preparation method and application of porcine epidemic diarrhea virus attenuated live vaccine chitosan microspheres. Background technique [0002] Porcine epidemic diarrhea (PED) is an acute, highly contagious intestinal disease caused by porcine epidemic diarrhea virus (PEDV). The morbidity and mortality of newborn piglets are close to 100%. Loss (Sun et al., EID, 2012). The main clinical features are vomiting, severe diarrhea and dehydration in piglets; in PEDV-infected pigs, the pathological changes of autopsy mainly show the atrophy and shedding of intestinal villi in the jejunum and ileum of pigs (Pensaert and Yeo, 2006). PED is very harmful to pigs, and pigs of all ages can be affected, but it is the most serious harm to suckling piglets, and the mortality rate of piglets within 20 days of age is over 95% (Timoney J F et al., 1988). [0003] Currently, PED is still widely pre...

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Problems solved by technology

In China, the live vaccine strain used to prevent porcine epidemic diarrhea is mainly the CV777 vaccine strain, but the PED vaccine immunized pig farms reported in my country in 2006 could not provide complete protection (Chen JF et al., 2010), recent research It was also found that the mutant strains in my country are dominant (Gao Y et al., 2013)

In 2011, diarrhea caused by a variant strain of porcine epidemic diarrhea broke out in pig farms immunized with CV777 attenuated live vaccine, which indicated that the traditional CV777 attenuated vaccine immunization could no longer effectively prevent diarrhea caused by the variant strain, and PED caused by the current variant strain It is ravaging around the world, so it is an urgent need for the pig industry in the world to develop a safe, efficient and cheap PEDV attenuated vaccine derived from the mutant strains isolated from PEDV.

Due to the complex environment in the stomach, the existing PED oral vaccine has a reduced effect

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