Abstract: Newcastle disease(ND) virus La Sota strain, infectious bronchitis( IB) virus M41 strain, egg drop syndrome(EDS76) virus HSH23 strain and avian encephalomyelitis(AE) virus Van Roekel strain, used as seed viruses, were separately inoculated into chicken embryos or duck embryos. Four virus fluids were harvested from the inoculated chicken embryos and duck embryos. After they were inactivated with formalin, the viruses were concentrated with the FILTRON cassette ultrafiltration system. A tetravalent inactivated oil emulsion vaccine a-gainst ND, IB, EDS76 and AE was prepared by using the concentrated viruses as antigen components, No 10 white mineral oil as adjuvant, Tween-80 and Span-80 as emulsifiers, merthiolate as preservative. The experimental results indicated that the vaccine was safe, and had no adverse effects for chickens. The earliest immunity was produced at 10-14 days post inoculation. The duration of immunity could last 180 - 360 days for adult birds. Potency tests showed that a single dose contained 50-123 PD50 of ND.Protective rates for NDV, IBV and AEV challenges were 100%, 8096-100% respectively. Mean hemagglutination inhibition(HI) titers for IB and EDS76 were ≥1:64 and ≥1:128 respectively.

Key words: Newcastle disease, Infectious bronchitis, Egg drop syndrome, Avian encephalomyelitis, Virus, Vaccine, Immunity

CLC Number: 

• S858.31