title: Immunogenicity and efficacy of fowlpox-vectored and inactivated avian influenza vaccines alone or in a prime-boost schedule in chickens with maternal antibodies.
abstract: Inactivated and fowlpox virus (FP)-vectored vaccines have been used to control H5 avian influenza (AI) in poultry. In H5 AI endemic countries, breeder flocks are vaccinated and therefore, maternally-derived antibodies (MDA) are transferred to their progeny. Results of three immunogenicity and one efficacy studies performed in birds with or without MDA indicated that the immunogenicity of an inactivated vaccine based on a H5N9 AI isolate (inH5N9) was severely impaired in chicks hatched from inH5N9-vaccinated breeders. This MDA interference was lower when breeders received only one administration of the same vaccine and could be overcome by priming the chicks at day-of-age with a live recombinant FP-vectored vaccine with H5 avian influenza gene insert (FP-AI). The interference of anti-FP MDA was of lower intensity than the interference of anti-AI MDA. The highest interference observed on the prime-boost immunogenicity was in chicks hatched from breeders vaccinated with the same prime-boost scheme. The level of protection against an antigenic variant H5N1 highly pathogenic AI isolate from Indonesia against which the FP-AI or inH5N9 alone was poorly protective could be circumvented by the prime-boost regimen in birds with either FP or AI MDA. Thus, the immunogenicity of vaccines in young chicks with MDA depends on the vaccination scheme and the type of vaccine used in their parent flocks. The heterologous prime-boost in birds with MDA may at least partially overcome MDA interference on inactivated vaccine.
authors.affiliation: Merial S.A.S., R&D, 254 rue M. Mérieux, 69007, Lyon, France. Alexandra.RICHARD-MAZET@merial.com.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Richard-Mazet
authors.affiliation: Merial S.A.S., R&D, 254 rue M. Mérieux, 69007, Lyon, France. Sylvain.GOUTEBROZE@merial.com.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Goutebroze
authors.affiliation: Merial S.A.S., R&D, 254 rue M. Mérieux, 69007, Lyon, France. Francois-Xavier.LE-GROS@merial.com.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Le Gros
authors.affiliation: Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, 934 College Station Road, Athens, Georgia, 30605, USA. David.Swayne@ars.usda.gov.
authors.forename: David E
authors.initials: DE
authors.lastname: Swayne
authors.affiliation: Merial S.A.S., R&D, 254 rue M. Mérieux, 69007, Lyon, France. michel.bublot@merial.com.
authors.forename: Michel
authors.initials: M
authors.lastname: Bublot
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis*; D002645:Chickens; D005586:Fowlpox / Q000276:immunology; D005587:Fowlpox virus / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control*; D015164:Vaccines, Inactivated / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated