Study On The Key Technology Of Monovalent Liquid Of Influenza Virus Vaccine

Influenza?referred to as flu?is an acute respiratory infection caused by influenza virus,and it is also a disease that is highly contagious and spreads rapidly.It is mainly transmitted by droplets in the air,contact between people or contact with contaminated objects.Vaccination against influenza is currently recognized as the most effective way to prevent the spread of influenza.At present,the influenza vaccines are mainly split influenza virus vaccines.The flu vaccine is prepared by mixing,filtering,and dispensing the flu virus monovalent stock solution.Among them,the production of monovalent stock solution is a key step in the production process,which can directly affect the quality and safety of influenza vaccine.At present,the industrialized production of split influenza virus vaccine monovalent stock solution is carried out by inoculating virus to 9-11 days old chicken embryos,harvesting virus solution,purification,lysis,inactivation and filtration to obtain influenza virus antigen.There are also experiments on influenza vaccines using MDCK cell culture^[1][2].The influenza vaccine production process lasts for a long time and the process is complicated.In order to obtain a safe,effective and stable split influenza virus vaccine,we studied the key technologies in the production process of chicken embryo production of split influenza virus vaccine monovalent stock solution.The World Health Organization annually recommends influenza strains for the current year based on global surveillance to prevent common and severe influenza viruses in different countries and regions of the world.HA?hemagglutinin?is the main antigenic protein on the surface of influenza virus,through which the immune response in the human body reflects the effectiveness of the influenza vaccine.Ovalbumin is an inevitable impurity in the process of producing influenza vaccine by chicken embryos,which can cause adverse reactions in human body.Therefore,the high recovery rate of HA and the high removal rate of ovalbumin are important indicators for improving the effectiveness of influenza vaccine and reducing adverse reactions.It has an important impact on the economics and safety of influenza vaccines.In this paper,the working seed batches of three strains of H1N1,H3N2 and B strains were inoculated to 11-day-old chicken embryos at different dilution factors.The virus culture was carried out at a certain culture temperature,and the virus solution was harvested to determine the hemagglutinin titer.The virus culture process was as follows:H1N1,H3N2were inoculated on the 11th embryo age,culture temperature was 34°C,cultured for 60hours to harvest allantoic fluid;B strain was inoculated on 11 days of embryonic age,culture temperature was 34°C,72 hours after harvesting allantoic fluid.The ovalbumin was removed by sucrose density gradient centrifugation after harvesting the allantoic fluid.The virus can be efficiently lysed by the addition of a non-ionic lysing agent?octyl sterol-9?.After adding PBS solution,it was filtered to remove the cleavage agent octoxyl ether-9.The virus lysate was inactivated by adding formaldehyde at room temperature of about 25°C and 2-8°C,respectively.After being diluted by filtration through a 0.2 um filter,a monovalent virus solution was obtained.Through the research on the key technology of the split influenza virus vaccine monovalent stock solution,the production process of the monovalent stock solution of split influenza virus vaccine is stabilized,which provides a reliable guarantee for the mass production of influenza vaccine.