Development Of Newcastle Disease, Infectious Bronchitis, Egg Drop Syndrome And Avian Influenza (H9 Subtype) Vaccine, Inactivated

In recent years, New Castle disease (ND), Infectious bursal disease (IBD), Eggs drop syndrome (EDS76) and Avian influenza (AI) outbreak frequently expecially in layer farms. Many kinds of vaccines were widely used to prevent these disesses, such as attenuated vaccine, inactivated vaccine and also combined inactivacted vaccine. In order to produce ND-IB-EDS76-H9 combined vaccine, three standard virus strains which are NDV, IBV and EDS76 were imported, and a low virulence and good immunogenicity H9 subtype AI virus (NJ02 strain) was selected. Then, the problem concentrtion technology was solved, and the ND-IB-EDS76-H9 oil emulsion inactivated combined vaccine was produced.1 The biological and immunological study was carried out with the three standard virus which imported from IVDC and three H9 subtype AI virus which isolated form epidemic areas.The results showed that three AI viruses were low-pathogenic and the viral titers in chick embryo breeding process could reach more than 108.3EID50/O.lml. And the NJ02 virus strain has the best immunogenicty which serum HI antibody titer could reach more than 10log2, and the protection efficacy of homologous virus challenge was 100%,80% of heterologous virus challenge. So the NJ02 virus strain was choosed as seedling strain. According to the<The Veterinary Biological Products Standard of People’s Republic of China, 2000 edition> the ND-IB-EDS76-H9 virus were rejuvenation with SPF chick embryo or susceptible duck embryo and identified completely. The stability of the standard viruses were promised by continue passage in SPF chick embryo or susceptible duck embryo, which from generation EltoE15. The standard virus stain were under various tests and then storaged at -20℃ or lyophilization. The exgenous virus test for generation 10 (E10) was fulfilled, chick embryo test conducted by our lab and SPF chich test conducted by Poultry Institution of Shandong. The result showed that these 4 virus strains were pure without any pollution of exogenous virus.2 The 4 virus antigens were concentrated by ultrafilter and the vaccine production process was studied. The result showed that the virus content and HA titer were positively correation with concentration ratio. There is no virus leakage in tail liquid after ultrafiltration and all of antigens have been recovered. Four virus antigen solution before and after concentration were under inactivete kinetics test respectively. The storage period under 2～8℃ of four inactivated antigens were tested by hemagglutination method. The resrult show that these inactivated antigens which have passed both inactivation and sterility test, the storage period under 2～8℃ was less than 4 months for NDV and EDS76 (AV 127strain), more than 9 months for IBV and more than 6 months for H9 subtype AIV (NJ02 strain).3 Quadruple inactivatied vaccine was produced by the mixture of four virus antigen in a proportion. One month old SPF chicks (Laihang),5 months old layers (Isa) and 9days old Sanhuang broilers were injected with single-dose, single-dose repeated and ultra-dose quadruple vaccine. There was no local or systemic reactions caused by the vaccine during 14 days after immunization and layers’ laying rate remained stable. All these indicate that the inactivated quadruple vaccine is safe.4 The standard of four antigen contend and quadruple vaccine efficacy of were studied by virus challenge and serological method, and then the products of antigen content and quality standard was made. Three batches of vaccine were tested in accordance with this standard. The result showed that all of these vaccine were meet the appropriate standard. Experiments showed that the immunity duration of this product was 3 months and the storage period was 12 months.