Study On The Optimization Of Virus Seed Technology For The Production Of Freeze-dried Nasal Spray Influenza Attenuated Live Vaccine

The live attenuated influenza vaccine of freeze-dried nasal spray is immunized by nasal spray,which can stimulate the cellular immunity,humoral immunity and mucosal immunity of human body.It has the advantages of relieving injection pain,lasting immune protection and cross protection,and is especially suitable for children’s vaccination.In this paper,we will introduce the optimization of influenza virus production process,improve the titer of virus species,so as to increase vaccine production and reduce production costs.Create greater economic benefits.In this study,SPF chicken embryo was used as the production matrix of influenza virus.After virus seed preparation,the technology research of H1N1（A/17/Brisbane/2018/8175（H1N1）pdm09）,H3N2（A/17/Brisbane/2018/3610（H3N2））and B（B/Colorado/06/2017-cdc-lv17b）influenza virus recommended by who was explored.The main results are as follows:1.With the virus titer as the reference index,the optimal preparation parameters of H1N1 virus were determined as follows:dilution 10^-5,culture temperature 32.5℃,culture humidity 75%,culture time 52 h,cold embryo time 20 h.2.With the virus titer as the reference index,the most suitable preparation parameters of H3N2 virus were determined as follows:dilution 10^-6,culture temperature 33.0℃,culture humidity 75%,culture time 60 h,cold embryo time 16 h.3.With the virus titer as the reference index,the most suitable preparation process parameters of type B virus were determined as follows:dilution 10^-6,culture temperature 31.5℃,culture humidity 65%,culture time 68H,cold embryo time 16h.4.Three types of influenza virus seed banks were established for commercial production of freeze-dried nasal spray live attenuated influenza vaccine.In this study,the production process parameters of virus seed were established to provide reference for the production of freeze-dried nasal spray live attenuated influenza vaccine.When applied to the production of single chicken embryo vaccine,the number of vaccine increased from 3.5 to 10.3,greatly saving costs,increasing production and creating greater economic value for enterprises.