Protective Efficacy of IBDV Winterfield H-2512 and SYZA-26 Immune-complex Vaccines against Recent Egyptian Very Virulent IBDV in Commercial Broiler Chickens

Eliwa, Mahmoud Galal El-Din; Talaat, Shaimaa; Tantawy, Laila; Abd El-Razik, Alaa; Sultan, Hesham

doi:10.21608/jcvr.2022.240929

Protective Efficacy of IBDV Winterfield H-2512 and SYZA-26 Immune-complex Vaccines against Recent Egyptian Very Virulent IBDV in Commercial Broiler Chickens

Document Type : Original Article

Authors

¹ Department of poultry diseases, Animal health research institute, Agriculture research center, Giza, Egypt.

² Department of Birds and Rabbits Medicine, Faculty of Veterinary Medicine, University of Sadat City, Menoufiya, Egypt

³ Department of pathology, Animal Health Research Institute, P. O. Box 264, Dokki, Giza, Egypt

10.21608/jcvr.2022.240929

Abstract

Infectious bursal disease is a highly contagious disease that affects chickens and results in huge economic losses worldwide. This study aimed to compare protection obtained by vaccination with two different IBDV immune-complex (ICX) vaccines. 225 one- day-old broiler chicks were divided in to 3 groups (75 birds in each group). Group 1 and 2 were vaccinated with Winterfield H-2512 and SYZA-26 ICX vaccines, respectively, according to manufacturer's instructions, the third group left as a control group. All groups were challenged on day-35 with vvIBDV local field isolate (GenBank accession no. KX646373). The protection assessment based on mortality rate, clinical signs, postmortem gross lesions, bursa to body weight ratio (BBR), seroconversion and mean severity index (MSI) of histopathological lesion scores was evaluated. Our results revealed that chickens vaccinated with immune-complex vaccines (G1 and G2) were completely protected clinically with no mortality compared with control non vaccinated chickens (G3) that showed typical IBDV clinical signs with (30%) mortality. In addition the BBR was significantly lower in SYZA-26 vaccinated birds than Winterfield H-2512 vaccinated and non-vaccinated birds, at 1-day pre-challenge, but at 7-days post-challenge the BBR was significantly lower in the non-vaccinated challenged group than the vaccinated challenged birds. The results of this study indicate that both Immune-complex vaccines can provide complete protection against mortality and clinical signs, but the Winterfield H-2512 ICX vaccine had a lesser effect on the bursa and higher immune response than the SYZA-26 ICX vaccine against challenge with the Egyptian vvIBDV.

Main Subjects