Prime-boost vaccination with a fowlpox vector and an inactivated avian influenza vaccine is highly immunogenic in Pekin ducks challenged with Asian H5N1 HPAI.
The efficacy of different vaccination schedules was evaluated in 17-day-old Pekin ducks using an experimental inactivated whole virus vaccine based on the H5N9 A/chicken/Italy/22A/98 isolate (H5N9-It) and/or a fowlpox recombinant (vFP-H5) expressing a synthetic HA gene from an Asian H5N1 isolate (A/chicken/Indonesia/7/2003). Full protection against clinical signs and shedding was induced by the different vaccination schemes. However, the broadest antibody response and the lowest antibody increase after challenge were observed in the group of ducks whose immune system was primed with the fowlpox vectored vaccine and boosted with the inactivated vaccine, suggesting that this prime-boost strategy induced optimal immunity against H5N1 and minimal viral replication after challenge in ducks. In addition, this prime-boost vaccination scheme was shown to be immunogenic in 1-day-old ducklings.
Steensels
M
M
Avian Virology & Immunology Unit, Veterinary & Agrochemical Research Centre, 99 Groeselenberg, B1180 Brussels, Belgium. miste@var.fgov.be
Bublot
M
M
Van Borm
S
S
De Vriese
J
J
Lambrecht
B
B
Richard-Mazet
A
A
Chanavat-Bizzini
S
S
Duboeuf
M
M
Le Gros
F-X
FX
van den Berg
T
T
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002642:Chick Embryo; D002988:Cloaca / Q000821:virology; D004372:Ducks; D005260:Female; D005587:Fowlpox virus / Q000235:genetics*; D006385:Hemagglutination Inhibition Tests; D007117:Immunization, Secondary; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000235:genetics / Q000276:immunology*; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control*; D009055:Mouth / Q000821:virology; D015164:Vaccines, Inactivated / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology; D017201:Virus Shedding / Q000276:immunology
D000914:Antibodies, Viral; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated; D014614:Vaccines, Synthetic