الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
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Abstract
The epidemiological investigation of 15 current infectious bursal disease (IBD) outbreaks among vaccinated chicken’s flocks during 2015-2016, These outbreaks were characterized by typical clinical signs and hemorrhagic gross lesions. The mortality rates in these flocks ranged between 5.25-20%.
IBDV was confirmed by detection of IBDV antigens using AGPT in bursal homogenates from acutely affected birds, Detection of IBDV RNA in all 15 bursal homogenates by amplification of 480 bp of VP2 gene using RT/PCR .
Laboratory experiments were designed to the efficacy of two commercially available live vaccines in Egypt, the HVT-vector and immune complex (ICX) IBDV vaccines in control of IBD by challenge with vvIBDV local field isolate ”N.B./Men.Egypt/15” at 25 or 32-day of age.
The results of protection against challenge with the vvIBDV local field isolate ”N.B./Men.Egypt/15”, after vaccination with HVT-vector and immune complex (ICX) IBDV vaccines subcutaneously on day-one revealed that there was complete protection against mortality in both vaccinated groups while the mortality was 5 % in non-vaccinated challenged group on day 25 and 10 % on day 32-day .
The results of serological response and degree of protection of HVT-vector and immune complex (ICX) IBDV vaccines in broiler chickens revealed early vaccinal take on day 21 in both vaccinated groups. and partial protection against bursal atrophy in both vaccinated groups 7dpc on day 25 while complete protection against bursal atrophy in group vaccinated with HVT-IBDV vector vaccine versus immune complex (ICX) IBDV vaccine that provided partial protection on day 32 when challenged on day 25 or 32 with vvIBDV local field isolate ”N.B./Men.Egypt/15”.