Preparation Of Combined Inactivated Vaccine Against Newcastle Disease And Avain Influenza

Newcastle disease (ND) and avian influenza (AI) are major constrains to poultryproduction. Many kinds of poultry and wild birds can be infected with AIV and NDV.Vaccination is the effective way to reduce the loss.A vaccine was prepared based on the improved processing technology, and the vaccine issafe and effective after the safety test, potency test, physical property test and contrast testwith another commercial product. The study included three parts.Part1: The improvement of the processing technology and the manufacture of thevaccine. The antigens were concentrated by the way of tangential flow filtration. This methodresulted in the higher content of virus and titer of HA. These two kinds of viruses can beinactivated in16h,37℃using0.1%formaldehyde. The aqueous phase was made by2timesconcentrated NDV La Sota and AIV H9subtype1:1, and then mixed with oil phase at a ratioof3:7. The vaccine was completely up to the standard of veterinarian biologicals after the test.Part2: The potency test of the vaccine. The vaccine was evaluated after challenge test,serologic test, immune duration test. It showed that21d after vaccination, all the SPFchickens in vaccinated groups were protected when challenged with NDV F48E9and AIV SY.All the groups can be protected when the titers of NDV antibodies over5.0log2and the AIVantibodies over6.0log2. If30d old SPF chickens were vaccinated with0.3ml, the immuneduration persisted18weeks. If the chickens were vaccinated with0.5ml, the immune durationpersisted36weeks.Part3: The comparison of combined vaccine with a commercial product. The vaccinewas compared with a commercial product. Both of them were all safe to SPF chickens andlayers. The immune duration reached more than6months. The vaccines stored between2℃to8℃for15months, and kept its immune efficacy and physical properties.