Screening Strains And Adjuvant For The Vaccine Of Broiler H9N2Avian Influenza Disease

Avian influenza virus (AIV) is recognized as one of the main poultry diseases.Many kinds of poultry and wild birds can be infected with Avian influenza. H9N2avian influenza virus is prevalent in whole world and had caused great economiclosses in China and the world. Also, H9N2avian influenza poses continuing threat toboth the animal and human public health. Vaccination is the effective way to reducethe loss and it plays a large role in avian influenza control and prevention in china.In order to consecutively observe the change of the H9N2AIV in East China,45representative H9N2subtype viruses isolated from poultry in East China during2008~2013have been sequenced and analyzed genetically in this study. Our resultsshowed that all HA genes of45viruses bear the A/DK/HK/Y280/97-like, then theirphylogenetic relationships are far away from existing vaccine strain. The resultsshowed that strains of A/DK/HK/Y280/97-like subsets have formed prevalentadvantage in a vast region in East China. Cross-positive serum hemagglutinationinhibition test and HA1amino acid sites change analysis showed that the currentepidemic H9N2virus antigenically has occurred more significant changes and leadingto the protective effect of existing vaccines are falling. Screening of new vaccinestrains is necessary.In this study, prevalent vaccine strains were selected from six H9N2subtypeavian influenza viruses isolated from East China during2012~2013by antigenicanalysis and immune efficacy and as prevalent vaccine candidates, then conductvaccine research product quality. The results showed that six strains of the virus invaccinated broiler JS04can withstand the domestic epidemic H9N2subtype avianinfluenza viruses, and it can be used as a new strain of avian influenza vaccine candidate.To evaluate the immune effects of adjuvant with different white oil in avianinfluenza virus, the biological safty, characteristic performance of emulsification,viscosity and stability were tested. Good quality oil was selected as adjuvant of avianinfluenza virus to compare the immune effect with the used commercial vaccinesunder identical condition. The results showed that the above performance of4whiteoils was met the technical standards of state medical white oil. The immune titer andpersistence of avian influenza vaccine with the adjuvant of domestic white oilMARCOL52imports was not only superior to other4white oil, but also to usedcommercial vaccines.