title: Genetic and antigenic variation of shedding viruses from vaccinated chickens after challenge with virulent Newcastle disease virus.
abstract: Newcastle disease virus (NDV) isolation was attempted from La Sota-vaccinated or unvaccinated chickens exposed to the virulent NDV variant E347Kmt. Shedding viruses were purified by plaque assay and then were sequenced for HN and F genes. The amino acid sequences of the F gene of all shedding viruses were identical to the sequence of the challenge virus. However, amino acid substitution occurred at four positions (70, 347, 466, and 517) in the HN protein among shedding viruses from vaccinated and challenged chickens but not from unvaccinated and challenged chickens. Amino acid substitution occurred more frequently at position 347 (K to G or V) in the HN protein compared with the other positions. There was minor antigenic variation between some of mutant viruses shed and challenge virus. However, none of mutant viruses had a significantly lower antigenic R value with La Sota virus compared with challenge virus E347Kmt. Our findings indicate that vaccinal immunity might facilitate an evolutional event through antigenic selection, genetic mutation among virulent virus populations shed from vaccinated flocks, or both.
authors.forename: Kang-Seuk
authors.initials: KS
authors.lastname: Choi
authors.forename: Soo-jeong
authors.initials: SJ
authors.lastname: Kye
authors.forename: Ji-Ye
authors.initials: JY
authors.lastname: Kim
authors.forename: Hee-Soo
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000940:Antigenic Variation; D002642:Chick Embryo; D002645:Chickens; D019143:Evolution, Molecular; D014644:Genetic Variation; D015707:HN Protein / Q000235:genetics / Q000276:immunology; D009521:Newcastle Disease / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D009522:Newcastle disease virus / Q000235:genetics* / Q000276:immunology*; D011201:Poultry Diseases / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012698:Serologic Tests / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics*; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral; D015707:HN Protein; C011894:La Sota vaccine; D014613:Vaccines, Attenuated; D014765:Viral Vaccines