Vaccination efficacy against Infectious Bursal Disease (IBDV) and serological indicators of antibody response in broiler chickens

Öz

Infectious bursal disease (IBD) remains a significant problem for the global poultry industry, particularly with the emergence of new and highly virulent variants over the past twenty years. This study aimed to determine the seroprevalence of infectious bursal disease virus (IBDV) in broiler chickens in the province of Sakarya, Türkiye and to evaluate the serological response to the commercial rHVT-IBD vaccine administered to these animals during incubation. A total of 456 serum samples were collected from 15 broiler farms, each with a capacity of 30,000 chickens (Of the total 456 samples, 420 were obtained from 14 farms, with 30 samples from each farm and 36 samples from one farm). The chicks were vaccinated with rHVT-IBD on day 0, and blood samples were collected on day 39. All sera were examined using ELISA to determine IBDV-specific antibody titres. Of the 456 samples, 449 (98.5%) were seropositive for Infectious Bursal Disease antibodies. ELISA titers were <800 in 14 chickens, 800–2500 in 12 chickens, 2500–4000 in 9 chickens, and ≥4000 in 421 chickens. The observed titer distribution indicates varying levels of humoral immune response following vaccination. Higher antibody titers may reflect a strong vaccine-induced immune response and could also be associated with possible additional immune stimulation under field conditions; however, ELISA results alone do not allow definitive differentiation between vaccine-induced and infection-induced antibodies. The findings suggest that early rHVT-IBD vaccination induces a robust immune response under field conditions. Serological monitoring and strict biosecurity practices may contribute to optimizing vaccine performance and controlling disease dynamics in broiler farms.

Anahtar Kelimeler

• Broiler chicken
• ELISA
• Infectious bursal disease (IBD)
• rHVT-IBD vaccine

Etik Beyan

The study protocol was reviewed and approved by Selcuk University Faculty of Veterinary Medicine Experimental Animals Production and Research Center Ethics Committee (SÜVDAMEK) (Approval no: 2025/20).

Broyler tavuklarda Enfeksiyöz Bursal Hastalığa (IBDV) karşı aşılama etkinliği ve antikor yanıtının serolojik göstergeleri

Öz

Bulaşıcı bursal hastalık (IBD), özellikle son yirmi yılda ortaya çıkan yeni ve son derece virülent varyantlar nedeniyle, küresel tavukçuluk sektörü için önemli bir sorun olmaya devam etmektedir. Bu çalışmanın amacı, Türkiye’nin Sakarya ilindeki broiler tavuklarda bulaşıcı bursal hastalık virusunun (IBDV) seroprevalansını belirlemek ve kuluçka döneminde bu hayvanlara uygulanan ticari rHVT-IBD aşısına karşı serolojik yanıtı değerlendirmektir. Her biri 30.000 kapasiteli 15 broiler çiftliğinden toplam 456 serum örneği toplanmıştır (Toplam 456 örneğin 420’si 14 çiftlikten (her bir çiftlikten 30 örnek olacak şekilde), 36’sı ise bir çiftlikten elde edilmiştir). Civcivler 0. günde rHVT-IBD ile aşılandı ve 39. günde kan örnekleri alındı. Tüm serumlar, IBDV'ye özgü antikor titrelerini belirlemek için ELISA kullanılarak incelendi. 456 örnekten 449'u (%98,5) Enfeksiyöz Bursal Hastalık antikorları açısından seropozitifti. ELISA titreleri 14’ünde <800, 12’sinde 800–2500, 9’unda 2500–4000 ve 421’inde ≥4000 idi. Gözlemlenen titre dağılımı, aşılama sonrası değişken düzeylerde humoral bağışıklık yanıtı olduğunu göstermektedir. Daha yüksek antikor titreleri, aşı kaynaklı güçlü bir bağışıklık tepkisini yansıtabilir ve saha koşullarında olası ek bağışıklık uyarımıyla da ilişkili olabilir; ancak, ELISA sonuçları tek başına aşı kaynaklı ve enfeksiyon kaynaklı antikorlar arasında kesin bir ayrım yapılmasına izin vermez. Bulgular, erken rHVT-IBD aşılamasının saha koşullarında güçlü bir bağışıklık tepkisi uyandırdığını göstermektedir. Serolojik izleme ve sıkı biyogüvenlik uygulamaları, aşı performansının optimize edilmesine ve broiler çiftliklerinde hastalık dinamiklerinin kontrol edilmesine katkıda bulunabilir.

Anahtar Kelimeler

• Broiler tavuk
• ELISA
• Enfeksiyöz bursal hastalığı (IBD)
• rHVT-IBD aşısı

Etik Beyan

Bu çalışma, Selçuk Üniversitesi Deneysel Araştırma ve Uygulama Merkezi Hayvan Deneyleri Etik Kurulu tarafından onaylanmıştır (Onay No: 2025/20)

Kaynakça

1. Du X, Ahmad L, Wang B, Ding M, Elsaid FG, Wen H, et al. Infectious bursal disease: distribution, pathogenesis and pathology. Pak Vet J. 2023;43(3):388-395.
2. Tibebu A, Yitbarek T, Bahiru A, Assefa, A. Seroprevalence and coinfection of infectious bursal disease in chickens raised under backyard production systems in Wag-Lasta, Amhara, Ethiopia. Res Sq. 2024;1:1-22.
3. Wagari AA. review on infectious bursal disease in poultry. J Health Econ Outcomes Res.2021;7(2):167.
4. Mili SA, Islam MS, Al Momen Sabuj A, Haque ZF, Pondit A, Hossain MG, et al. Cross‐sectional seroepidemiological study on infectious bursal disease in backyard chickens in the mymensingh district of Bangladesh. Vet Med Int. 2022;1-8.
5. Legnardi M, Franzo G, Tucciarone CM, Koutoulis K, Cecchinato M. Infectious bursal disease virus in Western Europe: The rise of reassortant strains as the dominant field threat. Avian Pathol. 2023;52(1):25-35.
6. Mosad SM, Elsayed MM, Hammad EM, Hendam BM, Ali HS, Eladl AH, et al. Genotype classification and pathogenicity of infectious bursal disease virus circulating in vaccinated broiler chicken farms. Vet Res Commun. 2024;48(5):3089-3104.
7. Hishamund P, Emikpe BO, Shyakaa A. Seroprevalence and associated factors of infectious bursal disease (IBD) in indigenous chicken in eastern province in Rwanda. J Immunoassay Immunochem. 2023;44(3):296-308.
8. Müller H, Mundt E, Eterradossi N, Islam MR. Current status of vaccines against infectious bursal disease. Avian Pathol. 2012;41(2):133-139.

9. Block H, Meyer-Block K, Rebeski DE, Scharr H, de Wit S, Rohn K, et al. field study on the significance of vaccination against infectious bursal disease virus (IBDV) at the optimal time point in broiler flocks with maternally derived IBDV antibodies. Avian Pathol. 2007;36(5):401-409.
10. Ravikumar R, Chan J, Prabakaran M. Vaccines against major poultry viral diseases: strategies to improve the breadth and protective efficacy. Viruses. 2022;14(6):1195.
11. Esaki M, Noland L, Eddins T, Godoy A, Saeki S, Saitoh S, et al. Safety and efficacy of a turkey herpesvirus vector laryngotracheitis vaccine for chickens. Avian Dis. 2013;57(2):192-198.
12. Okura T, Otomo H, Suzuki S, Ono Y, Taneno A. Oishi, E. Efficacy of a novel in ovo-attenuated live vaccine and recombinant vaccine against a very virulent infectious bursal disease virus in chickens. J Vet Med Sci. 2021;3(11)1686-1693.
13. Gelb Jr J, Jackwood DJ, Brannick EM, Ladman BS. Efficacy of recombinant HVT-IBD vaccines administered to broiler chicks from a single breeder flock at 30 and 60 weeks of age. Avian Dis. 2016;60(3):603-612.
14. Le Gros FX, Dancer A, Giacomini C, Pizzoni L, Bublot M, Graziani M, et al. Field efficacy trial of a novel HVT-IBD vector vaccine for 1-day-old broilers. Vaccine. 2009;27(4):592-596.
15. Williams RB. Anticoccidial vaccines for broiler chickens: pathways to success. Avian Pathol. 2002;31(4):317-353.
16. Sultan HA, Tantawi L, Gaballa A, Gad T. Appraisal of day-old vaccination with recombinant HVT-IBD-ND vaccine versus challenge with very virulent infectious bursal disease (vvIBDV) in broiler chickens. J Vet Res. 2025;7(1):313-325.
17. Esaki M, Dorsey KM, Leonard JD, Sato T. Efficacy of turkey herpesvirus vectored infectious bursal disease virus. The Poultry. [cited 2009]. Available from URL: https://www.thepoultrysite.com/articles/efficacy-of-turkey-herpesvirus-vectored-infectious-bursal-disease-virus.
18. Criado MF, Kassa A, Bertran K, Kwon JH, Silva MS, Killmaster L, et al. Efficacy of multivalent recombinant herpesvirus of turkey vaccines against high pathogenicity avian influenza, infectious bursal disease, and newcastle disease viruses. Vaccine. 2023;41(18):2893-2904.
19. Sedeik ME, El-Shall NA, Awad AM, Abd El-Hack ME, Alowaimer AN, Swelum AA. Comparative evaluation of HVT-IBD vector, immune complex, and live IBD vaccines against vvIBDV in commercial broiler chickens with high maternally derived antibodies. Animals. 2019;9(3):1-13.
20. Yilmaz A, Turan N, Bayraktar E, Gurel A, Cizmecigil UY, Aydin O, et al. Phylogeny and evolution of infectious bursal disease virus circulating in Turkish broiler flocks. Poultry science. 2019;98(5):1976-1984.
21. Kurtbeyoğlu GA, Akan M. Molecular characterisation of IBDV isolates in turkey revealed reassortant strains. Br Poult Sc. 2024;65(6):699-707.