title: Onset and long-term duration of immunity provided by a single vaccination with a turkey herpesvirus vector ND vaccine in commercial layers.
abstract: The onset and duration of immunity provided by a recombinant ND vaccine using HVT virus as vector (rHVT-ND) was followed up to 72 weeks of age in commercial layer chickens after single application or as part of two different vaccination regimes including conventional live and killed ND vaccines. Efficacy of the different vaccination programmes was checked, from 3 to 72 weeks of age, by serology as well as by challenges with a recent velogenic NDV isolate belonging to genotype VII. Assessment of protection was done based on the prevention of clinical signs and reduction of challenge virus shedding via the oro-nasal and cloacal routes. Single vaccination with the rHVT-ND vaccine at one day of age provided complete or almost complete (95-100%) clinical protection against NDV challenges from 4 weeks of age up to 72 weeks of age when the latest challenge was done. Shedding of challenge virus both by the oro-nasal and cloacal route was significantly reduced compared to the controls. Booster vaccination of rHVT-ND vaccinated birds with conventional ND vaccines significantly increased the level of anti-NDV serum antibodies and further reduced the oro-nasal excretion of challenge virus.
authors.affiliation: Scientific Support and Investigation Unit, Ceva Sante Animale, 5 Szállás utca, 1107 Budapest, Hungary. Electronic address: vilmos.palya@ceva.com.
authors.forename: Vilmos
authors.initials: V
authors.lastname: Palya
authors.affiliation: Scientific Support and Investigation Unit, Ceva Sante Animale, 5 Szállás utca, 1107 Budapest, Hungary.
authors.forename: Tímea
authors.initials: T
authors.lastname: Tatár-Kis
authors.affiliation: Scientific Support and Investigation Unit, Ceva Sante Animale, 5 Szállás utca, 1107 Budapest, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Mató
authors.affiliation: Scientific Support and Investigation Unit, Ceva Sante Animale, 5 Szállás utca, 1107 Budapest, Hungary.
authors.forename: Balázs
authors.initials: B
authors.lastname: Felföldi
authors.affiliation: Scientific Support and Investigation Unit, Ceva Sante Animale, 5 Szállás utca, 1107 Budapest, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Kovács
authors.affiliation: Innovation Strategy Department, Ceva Sante Animale, 10, avenue de la Ballastière, 33500 Libourne, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Gardin
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D026002:Herpesvirus 1, Meleagrid / Q000276:immunology*; D009521:Newcastle Disease / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D009522:Newcastle disease virus / Q000276:immunology*; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D018709:Statistics, Nonparametric; D014611:Vaccination / Q000592:standards / Q000662:veterinary; D014614:Vaccines, Synthetic / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*; D017201:Virus Shedding / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines
keywords: Newcastle disease; Recombinant vaccine; Vaccination; rHVT-ND vaccine