The Protective Efficacy of Recombinant Herpesvirus of Turkey (rHVT-ND-IBD) Vaccine against Velogenic Newcastle Disease Virus Genotype VII.1.1. | ||||
| Journal of Current Veterinary Research | ||||
| Volume 6, Issue 1, April 2024, Page 161-185 PDF (1.48 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jcvr.2024.352711 | ||||
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| Authors | ||||
| Hesham A. Sultan; Laila Tantawi; Taha Gad* | ||||
| Abstract | ||||
| Newcastle disease virus (NDV) outbreaks have been reported worldwide in vaccinated and non-vaccinated chicken farms, causing severe economic losses despite extensive vaccination. This study assessed the effectiveness of recombinant herpes virus of turkey (rHVT-ND-IBD) expressing the F protein of genotype VII with conventional genotype II vaccines against velogenic NDV genotype VII.1. 1. in broilers. Live ND vaccine with inactivated vaccine (G1), live ND vaccine with rHVT-ND-IBD vector vaccine and inactivated vaccine (G2), live ND vaccine with rHVT-ND-IBD vector vaccine (G3) and Live ND vaccine alone (G4) were the four immunization programs that were employed. Along with the control non-vaccinated group (G5). Birds were challenged at day 28. Clinical protection, seroconversion, histological alterations, and viral shedding following challenge were used to evaluate protection. The results showed mild clinical signs in G2 and G3 than in other groups, In addition, the mortality rates were 15%, 0%, 0% and 42.5% in G1, G2, G3 and G4, respectively, vs 85% in G5. Moreover, the tracheal virus shedding in G2 and G3 was significantly (p ≤ 0.01) reduced when compared with G1, G4 and G5. The mean lesion score (MLS) was significantly (p ≤ 0.01) decreased in G2 and G3 compared to other groups. The conclusion was that broilers immunized with rHVT-IBD-ND and NDV genotype II vaccinations exhibited full clinical protection against NDV genotype VII.1.1. After that, it is advised to give broilers rHVT-IBD-ND together with NDV genotype II vaccines to achieve the best possible clinical protection against genotype VII.1.1, particularly in endemic nations. | ||||
| Keywords | ||||
| Commercial broiler; HVT-ND vector vaccine; Genotype-matched vaccine; and Genotype VII.1.1 Newcastle disease virus | ||||
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