Qualty Control Of Key Processes On NDV Inactivated Vaccine Production

Newcastle Diseases is the acute and severe contactive infection in chicken and turkey caused by virus, which passes by as blood poisoning. Currently NDV breaks out world widely in many countries and areas and brings the great economic loss to the poultry industry. The ND virus mainly leads to the all-over or the respiratory diseases and may infect chicken, turkey, duck, partridge and other wild birds, which is presented as acute blood poisoning death and taking without syndrome. Presently, the vaccination is still the most effective treatment to prevent and control the Newcastle Diseases. The current using ND vaccines types in the world are the inactivated whole virus vaccine, the subunit vaccine, recombined live carrier vaccine and DNA vaccine. The inactivated vaccine which possesses the advantages of the simple production process, the good vaccination effect and the long protection period is used in many countries to effectively prevent the ND severe outbreak or epidemics. Therefore, producing safety and high-efficiency vaccine is essential to prevent and control this disease.This essay researches on production line of ND semi-product and finished inactivated vaccine, and deeply studies on the three quality control key-points during production process, which could provide the effective supporting on production perfection.(1). Chick embryo quality:Through summing up and analyzing the production data of continuous two years, considering the bacterial number and the QC conform rate, this essay deeply studies on the embryo quality to the production quality interfere regularity to emphasize the importance of the embryo quality control. The research indicates that embryo pre-incubation dead ratio is proportional to post-incubation dead ratio; embryo post-incubation dead ratio is proportional to harvest allantoic fluid bacteria counting, and the more bacteria counting in harvest allantoic fluid, the worse inactivation effect of active ingredient. Controlling pre-incubation dead ratio below14%will help to control post-incubation dead ratio below8%, and then will help to control harvest allantoic fluid bacteria counting below105. (2). Virus culture and inactivation method:Through comparing the four different virus culture setting times and combining the HA test result and production practical condition, this essay selects the most suitable virus culture time is72hours; through comparing the different set times base on the inactivation test and sterility test and considering the production practical condition, this essay selects the most suitable inactivation time is24hours.(3). Emulsification process:Through analyzing the factors which may interfere the vaccine stability, from emulsifying time, mixed speed, emulsifying speed, storage temperature and other aspects, this essay summarizes the suitable emulsifying time is42-48minutes, aqua phase adding into oil phase time is15-20minutes, the emulsifying speed is6000rpm and storage temperature is5℃-10℃.