title: Efficacy of intratracheal administration of Newcastle disease vaccine in day-old chicks.
abstract: Groups of day-old chicks with varying levels of parental antibody were vaccinated against Newcastle disease (B1 strain) with a commercially available device which simultaneously debeaks the chick and emits a fine spray of vaccine into its trachea. Some groups were also vaccinated (B1 or Lasota strain) with a commercially available vaccine sprayer at 9 days, 14 days, or 9 and 25 days of age. Response to vaccine was evaluated once each week during the experimental period of approximately 8 weeks HI titers were determined and 10 chicks were challenged with the Texas GB strain of Newcastle disease virus. In chicks with low to moderate levels of maternal antibody a satisfactory antibody response was attained by vaccination at 1 day of age, and in most cases resistance to challenge was evident by 3 weeks of age. Intratracheal vaccination of chicks with extremely high levels of maternal antibody had a minimal antibody response. All groups of chicks spray vaccinated at 9, 14, or 9 and 25 days of age showed a marked increase in antibody titer regardless of whether they had been vaccinated at 1 day of age.
mesh_terms: D000336:Aerosols; D000367:Age Factors; D000818:Animals; D000917:Antibody Formation; D002645:Chickens; D007112:Immunity, Maternally-Acquired; D009521:Newcastle Disease / Q000276:immunology / Q000517:prevention & control*; D009522:Newcastle disease virus / Q000276:immunology*; D014132:Trachea; D014765:Viral Vaccines / Q000008:administration & dosage*
chemical_list: D000336:Aerosols; D014765:Viral Vaccines