الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Avian influenza A virus subtype H9N2 is an important
contagious viral diseases for poultry populations across Asia and
Middle East. Recently, it was recorded that avian influenza H9N2
virus subtype contributed to the genesis of highly pathogenic H7N9
virus that caused lots of human deaths across Asia. Although using
large amount of H9N2 inactivated vaccines across Asia and Middle
East, the H9N2 virus cannot be controlled efficiently. Moreover,
WHO recommended the development of H9N2 virus vaccines due
to its pandemic preparedness and its high risk for the public health.
On the other hand, NDV is one of the most devastating
diseases of poultry worldwide causing big economic losses.
Although large amount of live and inactivated NDV vaccine are
currently in use, the virus still remains an ongoing threat for poultry
flocks in many countries in the world. However, NDV can be used
as a bivalent vector virus vaccine, in which one immunization can
give protection against two or more pathogens at the same time.
Moreover, NDV-based vaccines have been shown great success in
protection against many poultry pathogens such as avian highly
pathogenic H5N1, Infectious Bursal Disease Virus (IBDV) and
Infectious Laryngeotracheitis Virus (ILTV). Therefore, this study
aimed to develop an efficacious avian influenza virus vaccine.
The first objective of this study was to construct and
characterize recombinant NDV viruses expressing consensus H9
HA ORF. The first vaccine form NDV-H9Con, in which consensus
H9 HA was designed by alignment of available H9 HA sequences
from Middle Eastern and Far Eastern countries. Many studies showed that consensus-vaccine,s forms were able to provide more.