|Farag, Lamiaa Mohamed|
|Mohamed, Abdelstar Arafa|
Submitted to: American Association of Avian Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2011
Publication Date: 7/18/2011
Citation: Eggert, D.L., Spackman, E., Kim, M., Rue, C.A., Smith, D.J., Farag, L.O., Ahmed, N., Mohamed, A., Aly, M., Hassan, M., Fouchier, R., Suarez, D.L., Swayne, D.E. 2011. Determination of efficacious vaccine seed strains for use against Egyptian H5N1 highly pathogenic avian influenza viruses through antigenic cartography and in vivo challenge studies [abstract]. American Association of Avian Pathologists Annual Meeting, St. Louis, Missouri, July 16-19, 2011. CD-ROM. Interpretive Summary:
Technical Abstract: Since 2006, there have been reported outbreaks of H5N1 highly pathogenic avian influenza (HPAI) in vaccinated chickens in Africa and Asia. This study provides experimental data for selection of efficacious H5N1 vaccine seed strains against recently circulating strains of H5N1 HPAI viruses in Egypt. Initially, the serological responses of chickens vaccinated using commercially available vaccines (A/Vietnam/1203/04 and A/CK/Mexico/232/94) against HPAI were examined and low mean titers (30 GMT) to the challenge virus (A/ck/Egypt/CLEVB-HK213(9402NAMRU3)/2007 (H5N1)) were found for both vaccinated groups post-challenge. Mean serological titers to the vaccine virus were 91 GMT pre-challenge and 147 GMT post-challenge for both vaccinated groups, respectively. Another study was conducted and a vaccine made from a A/chicken/Egypt/CLEVB-HK213(9402NAMRU3)/2007 (H5N1) was found to decrease mortality. Post-challenge mean titers of 97 and 97 GMT were found to the challenge viruses (A/ck/Egypt/CLEVB-HK213(9402NAMRU3)/2007 (H5N1) and A/ck/Egypt/0831-NLQP/2008 (H5N1)), respectively. Antigenic cartography was used to select HPAI vaccine seed strains to test against challenge virus strains. Based on results from antigenic cartography, five vaccine seed strains (rgA/goose/Guangdong/1996 x PR8, A/ck/Mexico/232/1994 [H5N2], A/Ck/Egypt/06959-NLQP/2006, A/ck/Egypt/0865-NLQP/2008, and A/goose/Egypt/0920/2009) were selected for testing against two challenge viruses. In conclusion, studies combining both antigenic cartography and targeted in vivo challenge studies show promise for selecting the most efficacious vaccine seed stains.