Evaluation Of H7N9 Influenza Virus Subunit Vaccine

Since the first patient infected with the H7N9 influenza virus was discovered in Anhui in March 2013,the H7N9 flu virus has been popularized five times so far.Through the analysis of the genes of different strains,it was found that the gene type of H7N9 influenza virus was mainly mutated by gene mutation and recombination.The first four epidemic strains were mainly low pathogenic avian influenza virus,the fifth epidemic is the highly pathogenic avian influenza virus.In summary,the H7N9 flu virus is still undergoing constant variability.As far as the current evolutionary trend is concerned,the virus is becoming more and more threatening to humans.Therefore,It is urgent to develop vaccine that can prevent H7N9 flu.In this paper,a novel subunit protein vaccine was studied,and HA on the LPAIV strain A/Anhui/1/2013/H7N9 and HPAIV strain A/chicken/Guangdong/SZBJ0011/2017/H7N9 influenza virus membrane was selected as the vaccine immunogen,considering that the immune effect of the subunit protein vaccine is poor,we immunize the mice by fully mixing the HA recombinant protein with aluminum adjuvant,MF59,Freund's adjuvant and white oil adjuvant.After the vaccine is immunized,the mouse serum is collected and blood is used.The content of antibody in serum was detected by coagulation inhibition and ELISA.The lung tissue was collected after immune challenge.The virus content in lung tissue was detected by MDCK cells.The body weight change rate and survival rate were observed after challenge.The results showed that the H7 protein-binding adjuvant can induce strong antibody levels in the body after boosting immunity,and eliminate the H7N9 influenza virus in mouse lung tissue and inhibit the proliferation of the virus,thereby protecting the mice in a short time after attacking,return to normal levels.At the same time,it can be seen from the above experimental results that there is no significant difference in the immune effect between different adjuvants.Subsequently,different immunization doses were set for 2013anhui HA protein and 2017BJ0011 HA protein.The antibody content in the serum after immunization and the body weight change and mortality of the mice after challenge were detected by hemagglutination inhibition test and ELISA test.The antigens of these two HA proteins were not dose dependent.