Development and application of an improved infectivity assay for the standardization of avian encephalomyelitis vaccines.
An improved infectivity assay for avian encephalomyelitis viruses (AEVs) is described in which susceptible 7-day-old chicken embryos were inoculated with dilutions of a particular AEV strain and, after incubation for 12 days, the presence of viral antigen in brains was detected by an enzyme-linked immunosorbent assay (ELISA). The assay (the brain antigen ELISA), which may be used for the titration of both egg-adapted and non-egg-adapted strains, can be completed within 12 days. For the conventional essays of non-egg-adapted vaccine strains, embryos are infected in ovo and hatched chickens examined for neurological signs after 3-4 weeks. No animal handling facilities are required with the brain antigen ELISA and results of comparable sensitivity to the hatch-out assay were obtained.
Shafren
D R
DR
Faculty of Medicine, University of Newcastle, N.S.W., Australia.
Tannock
G A
GA
D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D001681:Biological Assay; D001921:Brain / Q000276:immunology; D002642:Chick Embryo; D001350:Encephalomyelitis Virus, Avian / Q000276:immunology*; D004770:Enterovirus / Q000276:immunology*; D004769:Enterovirus Infections / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D014765:Viral Vaccines / Q000032:analysis* / Q000592:standards
D000956:Antigens, Viral; D014765:Viral Vaccines