Studies On Purification Technology Of Live Vaccine Virus Of Porcine Reproductive And Respiratory Syndrome

Porcine reproductive and respiratory syndrome has become more and more harmful since it was found. The disease was classfied as classⅠepidemicin in2009by Ministry of Agriculture of China and has become the most hazadous disease forswine production in China.Vaccine immunity is the best way to prevent and control the disease. At the present time, it is most urgent to develop new vaccine that is effective, safe and stable.The Ministry of agriculture’s approval of temporary production code for live vaccine of high pathogenic porcine reproductive and respiratory syndrome （TJM-F92strainwas obtained by my companyin2010and formal production code was obtained in2011. With prodction of more than one hundredmillion vaccine in the market, the production technology is stable and the product quality has won good comments by farmers. On this basis, my company intended to purify porcine reproductive and respiratory syndrome virus in order to establish production process of high purity, high recovery and good stability.Tangential Flow Filtration was adopted in the study to purify porcine reproductive and respiratory syndrome virus and remove mixed protein, DNA fragment dirt,etc from the virus cultured fluid which aims at improving purity of the porcine reproductive and respiratory syndrome virus. Three tests were performed with the yield coefficient of the virus cultured fluid before and after purification monitored, TCID50and protein content determined and the film bag for some miscellaneous protein and DNAfragments of impurity removal efficiency examined. The test results show that the purified virulence increased dramatically—by five times on average in the five times concentration, which indicates that there is no loss of effective virus. The removal rate of impurity protein is8.17%in the five times dialysis tests. And by removing interference of protein and impurities, more efficient production of cell cytopathic and better effect of virus expression is achieved.Purified virus cultured fluid and the virus cultured fluid unsettled purified conventional were used to produce vaccine. The virus level of the former with improvement of physical characteristics is fine times that of the latter. With no clinical abnormal phenomena in safety inspection of the purification vaccine, it is clear that the vaccine is of good safety.