title: A model for the transfer of passive immunity against Newcastle disease and avian influenza in specific pathogen free chickens.
abstract: Chicks possess maternally derived antibody (MDA) against pathogens and vaccines previously encountered by the dams. This passive immunity is important in early life, when the immune system is immature and unable to fight off infection. On the other hand, MDA can also affect the development of the immune system and interfere with vaccination against avian diseases such as Newcastle disease (ND) and avian influenza (AI). The effect of MDA is generally investigated by studying the progeny of vaccinated dams, which is time-consuming, poorly flexible and expensive. Moreover, the antibody titres obtained are not homogeneous. In this study, a model was developed to offer a faster, more reproducible and cheaper way to study passive immunity in specific pathogen free chickens by injection of a polyclonal serum into the egg yolk at embryonic day 14, combined with an intraperitoneal injection at day 1. A satisfactory model, with consistent, homogeneous antibody titres, as well as persistence close to natural passive immunity, could be obtained for ND virus. On the other hand, the application of this optimized protocol in an H5 AI context induced only a low artificial passive immunity compared with that described in the literature for the progeny of AI vaccinated dams. This artificial model should facilitate future studies regarding the effect of passive immunity on vaccine efficacy at a young age and its effect on immune system development.
authors.affiliation: a Avian Virology and Immunology Unit , Veterinary and Agrochemical Research Centre , Brussels , Belgium.
authors.forename: Amélyne
authors.initials: A
authors.lastname: Lardinois
authors.forename: Thierry
authors.initials: T
authors.lastname: van den Berg
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Lambrecht
authors.forename: Mieke
authors.initials: M
authors.lastname: Steensels
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002645:Chickens / Q000276:immunology* / Q000821:virology; D004531:Eggs / Q000821:virology; D005260:Female; D007112:Immunity, Maternally-Acquired; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D005585:Influenza in Birds / Q000276:immunology* / Q000821:virology; D009521:Newcastle Disease / Q000276:immunology* / Q000821:virology; D009522:Newcastle disease virus / Q000276:immunology*; D015203:Reproducibility of Results; D013047:Specific Pathogen-Free Organisms; D014611:Vaccination / Q000662:veterinary
chemical_list: D000914:Antibodies, Viral