Infectious bursal disease (IBD) viruses continue to cause considerable economic losses in the Egyptian poultry industry. The purpose of this study was to investigate the molecular features of IBDV isolated in Egypt from 2021 to march 2022, and assess the pathogenicity, immunogenicity, and protection of the IBD immune-complex vaccinations (Transmune®-CEVA vaccine). Twenty-three field samples (bursa of Fabricius) were collected from broiler farms and a highly variable region encompassing VP2 gene was targeted for IBDV screening utilizing RT-PCR. Out of 23 tested farms, 19 were positive by RT-PCR.Six positive samples were chosen for viral isolation, sequence, and phylogenetic analysis. Phylogenetically, five of the strains under study belonged to the very virulent (vvIBDV) strains, with 95-98% resemblance to Giza 2008 belonging to Genogroup 3 of IBDV strain. The remaining strain were identified as a vaccination strain (Genotype 1) and  matched the winter field 2512 vaccine strain by a similarity percentage of 96%. One day old commercial chicks were vaccinated (Transmune®-CEVA vaccine) then challenged with selected very virulent strain (OP056767). The Fabricius Bursa was examined grossly and histologically. Furthermore, the Bursal Body Weight Ratio and Bursa Index were computed. The transmune IBD vaccination was able to elicit a high ELISA mean titer of 3179 at 32 days of age (4 day post challenge). Moreover, the greater raised mean ELISA titers of 9264 (38day) and 9354 (42 day) post vaccination, indicating that the challenge IBDV serves as booster immunization. Beside the Efficacy of transmune®-CEVA vaccine in reducing mortality in comparison to Pathogenicity group. The bursal body weight ratio and index demonstrate that the IBD vaccine was able to indicate an inflammatory response in the bursa of fibricia, resulting in a better immunological response and the safety of the Transmune®-CEVA vaccine. Finally, our findings show the dual circulation of both G1 and G3 strain in poultry flocks, and the immune-complex vaccination is still effective in protecting commercial broiler chicks against dominant circulating vvIBD strains.