الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
Abstract
Highly Pathogenic Avfrom this study, the following points were performed:
A) Isolation and identification of newly avian influenza (AI) strain
from infected Egyptian flocks farms:
1. Fresh samples of several dead and sick birds from infected flock
(had a history of AI clinical signs and gross lesion) were collected.
The isolated AI viruses cause embryo deaths as early as 24 - 48
hours post inoculation and all samples showing complete positive
haemagglutination.
2. The isolated virus was serologically belonged to H5-AIV positive
while they were ND and EDS negative. The result of HI test for
the AIV new Egyptian isolate was 10.3 log2 H5N1 antisera.
3. The HA titer for AI virus was 7 log2.
4. The intravenous pathogenicity index (IVPI) value of the AI virus
was 2.1. So, it considered to be a highly pathogenic AIV for
chicken.
5. The AIV titer was expressed as EID50 and ranged from 1011.5 for
AI virus.
6. The results of RT-PCR test for M gene confirmed that the isolate
virus was AIV-type A positive. While, genetic identification of the
AI isolate virus by RT-PCR using specific primers for H5N1
yielded a strong positive reaction. The results were negative
against H9N2 and ND primers.
7. The phyelogenetic tree of the Egyptian AI isolate was:
The AIV newly Egyptian strain isolated at 2016 was identical and
fell into the classical group of the Egyptian AI viruses (clade
2.2.1.2.), which is dominant in Egypt since 2012 till now.
Also, the isolated AIV at 2016 was named as A/Ch/Egypt/Qal-
3/2016 (H5N1) with accession number MF664437 on gene bank.
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SUMMARY
Dalia M. Omar, (2018), Ph.D., Fac. Agric., Ain Shams Univ.
When the new isolated 2016 AIV compared with the other exisolated
challenge viruses isolated at 2008, 2010, 2012 and 2015,
the % of identity were 94, 92, 98 and 99%, respectively.
B) Results of in vivo and in vitro studies for vaccines efficacy showed
that; The high antibody titer recorded at 4 weeks post vaccination
were 8, 8.1, 8.6, 10.3, 8.8 log2 for krND-AI, krBacu-AI+ND,
kH5N1, kH5N2 and kAI+ND vaccines respectively. Meanwhile HI
titer induced by rHVT-AI vaccine was 7.1 log2 at 7th WPV.
C) The protection % of the tested AI vaccines at 4 weeks post
vaccination and 4 months post vaccination in chickens challenged
with local HPAI 2.2.1.1. variant 2008 challenge virus were as
follow:
The protection % of birds vaccinated with live rHVT-AI, rFPAI/
Scot and rFP-AI/Ire and challenged with variant local HPAI
2.2.1.1. challenge virus (2008) were 93.3%, 20% and 33.3%,
respectively. Moreover, The protection % of groups vaccinated
with inactivated recombinant krND-AI and krBacu-AI+ND were
86.7% and 93.3%, while the protection % for the chicken groups
vaccinated with the inactivated whole AI virus either kH5N1,
kH5N2 and kAI+ND were 100%, 92.9% and 85.7%, respectively.
It was observed that the protection % at 4 MPV were 20%, 33.3%,
93.3%, 86.7%, 93.3%, 100%, 92.9% and 85.7% for rFP-AI/Scot,
rFP-AI/Ire, rHVT-AI, krND-AI, krBacu-AI+ND, kH5N1, kH5N2
and kAI+ND vaccines, respectively.
The results of virus shedding from the vaccinated birds challenged
with variant 2.2.1.1 HPAI virus in case of live rFP-AI/Scot and
rFP-AI/Ire showed very low level of reduction in virus shedding
ranged from 0.3-0.7 for virus reisolation. But the virus shedding in
case of krND-AI and krBacu-AI+ND was reduced with a level
ranged 3-3.2, respectively. The rHVT-AI vaccine evoked a
reduction in the challenge virus dose shed from respiratory tract
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SUMMARY
Dalia M. Omar, (2018), Ph.D., Fac. Agric., Ain Shams Univ.
equal 3.4. Also, it was showed that there was reduction in variant
challenge virus replication either 2.5, 3 and 3.5 EID50 from
tracheal swabs of chicken vaccinated with inactivated whole virus
either kAI+ND, kH5N1 and kH5N2 vaccines, respectively. It is
observed that there was a reduction in the viral shedding at 4 MPV
from tracheal swabs with levels of 3.0, 0.1, 0.4, 2.0, 2.7, 3.7, 2.6 &
2.2 EID50 for groups vaccinated with rHVT-AI, rFP-AI/Scot, rFPAI/
Ire, krND-AI and krBacu-AI+ND, kH5N1, kH5N2 and
kAI+ND vaccines, respectively.
when examined viral shedding by qrRT-PCR, it was found that for
rFP-AI/Scot, rFP-AI/Ire vaccines, the results were positive for
variant challenge virus after 1st and 2nd challenges as compared
with rHVT-AI, krND-AI and krBacu-AI+ND, kH5N1, kH5N2 and
kAI+ND vaccines, which induced a great reduction in virus
shedding from the vaccinated birds after 1st challenge (4WPV) and
2nd challenge (4MPV).
D) The protection % of the tested AI vaccines at 4 weeks post
vaccination and 4 months post vaccination against challenge with
local HPAI 2.2.1.2. classical 2016 challenge virus revealed that:
The protection % of the vaccinated and control group, challenged
with local HPAI 2.2.1.2 challenge virus. The protection % of live
rHVT-AI, rFP-AI/Scot and rFP-AI/Ire were 93.3%, 26.7% and
40%, respectively, while the inactivated recombinant krND-AI
and krBacu-AI+ND protect the chicken against challenge virus
with a ratio of 86.7% and 93.3%. Also, chicken vaccinated with
inactivated kH5N1, kH5N2 and kAI+ND were protected with a
percentage reached to 100%, 93.3% and 86.7%, respectively after
1st challenge (4WPV). While after the 2nd challenge (4MPV) the
results were 13.3%, 26.7%, 86.7%, 80%, 86.7%, 100%, 86.7%
and 80% for rFP-AI/Scot, rFP-AI/Ire, rHVT-AI, krND-AI,
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SUMMARY
Dalia M. Omar, (2018), Ph.D., Fac. Agric., Ain Shams Univ.
krBacu-AI+ND, kH5N1, kH5N2 and kAI+ND vaccines,
respectively.
The results of virus shedding from the vaccinated birds challenged
with classical 2.2.1.2 HPAI virus in case of live rFP-AI/Scot and
rFP-AI/Ire there was very low level of challenge virus reduction
ranged from 0.5-0.7 for virus reisolation, but the virus shedding in
case of krND-AI and krBacu-AI+ND was reduced with a level
ranged 3.5-4.8, respectively, while the rHVT-AI vaccine evoked a
reduction in the challenge virus dose shed from respiratory tract
equal 5.5. Also, it was showed that there was reduction in variant
challenge virus replication either 5.5, 4.5 and 4.0 EID50 from
tracheal swabs of chicken vaccinated with inactivated whole virus
either kAI+ND, kH5N1 and kH5N2 vaccines, respectively, at 4
MPV it is observed that there was a reduction in the viral shedding
from tracheal swabs with levels of 5.1, 0.1, 0.3, 3.4, 5.1, 5.1, 4.2 &
3.9 EID50 for groups vaccinated with rHVT-AI, rFP-AI/Scot, rFPAI/
Ire, krND-AI and krBacu-AI+ND, kH5N1, kH5N2 and
kAI+ND vaccines, respectively.
Examination of virus shedding by qrRT-PCR: It was found that for
rFP-AI/Scot, rFP-AI/Ire vaccines, the results were positive for
variant challenge virus after 1st and 2nd challenges as compared with
rHVT-AI, krND-AI and krBacu-AI+ND, kH5N1, kH5N2 and
kAI+ND vaccines where there was a great reduction in virus
shedding from the vaccinated birds after 1st challenge (4WPV) and
2nd challenge (4MPVian Influenza (HPAI) H5N1 virus, poses a
serious threat to animal and public health worldwide. Since late 2003, the
virus has spread to over 60 countries in Asia, Europe and Africa leading
to death or culling of hundreds of millions of poultry and occasional
transmission to humans revealing its pandemic potential. Effective
vaccination against HPAI H5N1 would protect commercial poultry and
would thus provide an important control measure by reducing the
likelihood of bird-to-bird as well as bird-to-human transmission.
Therefore, the development of efficacious influenza vaccines is of high
veterinary and public health importance.
So, the present study was designed for detection of the
effectiveness of different recombinant AI vaccine types in prevention of
poultry infection with AI and reducing the environmental contamination
through:
1. Studying the immune response of the recombinant AI vaccines in
protection of chicken against avian flu.
2. Comparative study between the immune response against the
recombinant and inactivated AI vaccines.
3. Studying the efficacy of the recombinant AI vaccines against
classical and variant clades of highly pathogenic AI challenge virus.
4. Studying the efficacy of recombinant AI vaccines for reduction of
viral shedding.
5. Isolation of new local AIV isolate in Egypt to know antigenic
variation between the new isolate 2016 and other isolates in 2008,
2010, 2012 and 2015.