Title: Inadequate protection of ducks and geese against H5N1 high pathogenicity avian influenza virus by a single vaccination Authors
Submitted to: Proceedings of Southern Conference on Avian Diseases
Publication Type: Abstract Only
Publication Acceptance Date: December 15, 2009
Publication Date: January 25, 2009
Citation: Eggert, D.L., Swayne, D.E. 2009. Inadequate protection of ducks and geese against H5N1 high pathogenicity avian influenza virus by a single vaccination [abstract]. Proceedings of Southern Conference on Avian Diseases. January 25-26, 2010, Atlanta, Georgia. p. 32. Technical Abstract: Ducks and geese are an important sustainable food source in developing countries. Few studies have been conducted to test vaccine efficacy in either ducks or geese. This study was conducted to investigate whether a single vaccination could protect White Pekin ducks and White Chinese geese against challenge from A/chicken/Indonesia/7/03 (H5N1). One week old White Pekin ducks and 1 week old White Chinese geese were bled and vaccinated subcutaneously with 200 µL of an individual vaccine. Three weeks post vaccination, animals were challenged intranasally with 200 µL of 10*6 EID50 A/chicken/Indonesia/7/03 (H5N1). Oropharyngeal and cloacal swabs were taken on days 0, 1, 2, 3, 4, 7, 10 and 14 post-challenge. Blood was taken for serum before vaccination, 3 weeks post vaccination and 2 weeks post challenge. Ducks and geese were euthanized at 2 weeks post challenge. Our study showed greater oropharyngeal shedding compared to cloacal shedding in both ducks and geese. No mortality was observed with ducks, but was observed in the sham group for geese. Vaccines used resulted in varying decreases in the amount of virus shed, but no vaccine completely blocked virus shedding for either ducks or geese. Vaccines were observed to have no effect on the total number of ducks or geese orally or cloacally shedding virus. The vaccine made using the challenge virus as the seed strain was by far the most protective in limiting the quantity and time window of virus shedding. Mixed results were observed when cross hemagglutination-inhibition (HI) titers were examined and then compared to mortality and shedding data for both ducks and geese. Use of single vaccination is not sufficient to protect White Pekin ducks and White Chinese geese against high pathogenicity avian influenza (HPAI) (H5N1). More research is needed to discern and test suitable vaccine candidates to develop appropriate vaccines and vaccination regimens for ducks and geese given the species differences from gallinaceous poultry.