Comparative Immunological Studies on Avian Influenza Live Fowl Pox Vector H Subtype and Inactivated Avian Influenza H5 N5 Vaccines

Abstract: In a trial to control the wide spread of Highly pathogenic avian influenza (HPAI) H5N1 virus
outbreaks among poultry flocks in Egypt, many inactivated oil adjuvant AI virus vaccines were used. All
of these vaccines were either low pathogenic H5N2 AI viruses or genetically re-assorted H5N1 AI virus. In
the current study a recombinant fowl pox-avian influenza (AI) H5 vaccine (reFP-AIV-H5); expressing the
hemagglutinin of the A/turkey/Ireland/1378/83 (H5N8) AI isolate; was evaluated in comparison with the
genetically re-assorted inactivated H5N1strain A/Goose/Guandong/1/96 and inactivated H5N2
strainA/CK/Mexico/232/CPA/94 in SPF chickens. The potency of the 3 vaccines using HI test against
homologous and heterologous AI antigens were 5, 10.2 and 7.7 log2 HI unites, respectively. While, HI
titre against the heterlogous AI local antigen prepared from A/chicken/Egypt/12378 N3-CLEVB/2006/H5N1
strain were 2, 6.4 and 5 log2 HI unites, respectively and 0, 4.6 and 0 log , respectively against the heterologous 2
AI local antigen prepared from A/chicken/Egypt/9402 NAMRU3-CLEVB 213/2007/H5N1 strain. On the
other hand, the efficacy of the 3 vaccines in SPF chickens was studied. The protection percentages were
40, 90 and 80% against HPAI isolate 2006 and were 0, 31 and 19 against HPAI isolate 2007, respectively. AIV
shedding was detected and titrated in both vaccinated and control challenged birds. It was concluded that
the reFP-AIV-H5 vaccine is not suitable to be used to protect poultry flocks in Egypt against the circulating
AIV either 2006 or 2007 strains.
Publication year 2009
Pages 390-394
Organization Name
Author(s) from ARC
Publication Type Journal
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