Veterinary and Comparative Biomedical Research

Veterinary and Comparative Biomedical Research

Comparative Efficacy of Two Commercial FAdV-4 Vaccines against Virulent Challenge in Broiler Chickens

Articles in Press

Document Type : Short Communication

Authors
Arash Ghalyanchi Langeroudi 1
Zahra Ziafati Kafi 1
Soroush Sarmadi 1
Fahimeh Jamiri 1
Alireza Bakhshi 1
Rima Morshed 2
Mahtab Heidarpour 1
Fatemeh Gharagazlou 1
Alireza Vafadar 1
Hirbod Sheikhi 1
Seyed Alireza Rezaee 1
Farnood Shahamati 1
Hossein Hosseini 3
1 Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
2 Agriculture and Veterinary Group, Faculty of Encyclopedia, IHCS, Tehran, Iran
3 Department of Avian Diseases, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Alborz, Iran
10.22103/VCBR.2026.26663.1122
Abstract
Hepatitis–hydropericardium syndrome (HHS), caused by fowl adenovirus serotype 4 (FAdV-4), is a major cause of acute mortality in broiler chickens worldwide. Despite the availability of commercial vaccines, their protective efficacy under virulent challenge conditions may differ. This study aimed to compare the immunogenicity and protective efficacy of two commercial FAdV-4 vaccines in broiler chickens. One hundred one-day-old Arian broiler chicks were randomly allocated into four experimental groups (20 birds per group), with five additional contact birds per group to evaluate horizontal transmission. Birds in Groups 3 and 4 were vaccinated at 21 days of age with commercial FAdV-4 vaccines from Company A and Company B, respectively. At 42 days of age, birds in Groups 2, 3, and 4 were challenged intramuscularly with a virulent FAdV-4 strain. Serum samples collected prior to challenge were analyzed for FAdV-4-specific antibodies using an ELISA assay. Birds were monitored for clinical signs, mortality, and gross pathological lesions for seven days post-challenge. Before challenge, birds vaccinated with Company B developed significantly higher ELISA antibody titers (1440 ± SEM) than those vaccinated with Company A (910.5 ± SEM) and unvaccinated controls (P < 0.0001). Following challenge, 100% mortality with severe hepatic necrosis and hydropericardium was observed in the unvaccinated challenged group and in birds vaccinated with Company A. In contrast, birds vaccinated with Company B showed complete protection, with no mortality, no gross pathological lesions, and no mortality among contact birds. Commercial FAdV-4 vaccines differed markedly in protective efficacy. Elevated ELISA antibody titers alone were not predictive of protection, emphasizing the need for rigorous evaluation and careful selection of vaccines to effectively control HHS in broiler flocks.
Keywords
Broiler Chicken
Commercial FAdV-4 Vaccines
Fowl adenovirus-4
HHS
Vaccine Efficacy
Subjects
  1. Schachner A, Grafl B, Hess M. Spotlight on avian pathology: fowl adenovirus (FAdV) in chickens and beyond—an unresolved host–pathogen interplay. Avian Pathol. 2021;50(1):2-5. https://doi.org/10.1080/03079457.2020.1804535
  2. Harrach B. Adenoviruses across the animal kingdom: a walk in the zoo. FEBS Lett. 2019;593(24):3660-3687. https://doi.org/10.1002/1873-3468.13678
  3. Pan Q, Yang Y, Shi Z, Liu L, Gao Y, Qi X, et al. An inactivated novel genotype fowl adenovirus 4 protects chickens against the hydropericardium syndrome that recently emerged in China. Viruses. 2017;9(8):216. https://doi.org/10.3390/v9080216
  4. Li H, Wang J, Qiu L, Han Z, Liu S. Fowl adenovirus species C serotype 4 is attributed to the emergence of hepatitis-hydropericardium syndrome in chickens in China. Infect Genet Evol. 2016;45:230-241. https://doi.org/10.1016/j.meegid.2016.09.006
  5. Zhen C, Zhang M, Ji C, Deng Y, Chen H, Deng X, et al. Hydropericardium syndrome caused by fowl adenovirus serotype 4 in a 100-day-old laying flock. Transbound Emerg Dis. 2018;65(6):1411-1417. https://doi.org/10.1111/tbed.12932
  6. Oliver-Ferrando S, Dolz R, Calderón C, Valle R, Rivas R, Pérez M, et al. Epidemiological and pathological investigation of fowl adenovirus infection in broiler flocks in Spain. Avian Pathol. 2017;46(3):288-296. https://doi.org/10.1080/03079457.2016.1264082
  7. Liu A, Wang H, Zhang Y, Wang Y, Li K, Qi X, et al. Advances in vaccine development of the emerging novel genotype fowl adenovirus 4. Front Immunol. 2022;13:916290. https://doi.org/10.3389/fimmu.2022.916290
  8. Bayraktar E, Aydin O, Şimşek A, Çöven F. Molecular characterisation of fowl adenovirus associated with hydropericardium hepatitis syndrome in broiler and layer breeders in Azerbaijan. BMC Vet Res. 2024;20(1):241. https://doi.org/10.1186/s12917-024-04085-7
  9. Kaján GL, Affranio I, Tánczos B, Chimeno Zoth S, Taboada E, Gomez E, et al. An emerging new fowl adenovirus genotype. Infect Genet Evol. 2019;73:142-146. https://doi.org/10.1016/j.meegid.2019.04.027
  10. Xie Q, Wang W, Xie Z, Lin S, Fang L, Huang J, et al. Fiber-2-edited live attenuated vaccine for fowl adenovirus 4. Vet Res. 2021;52(1):122. https://doi.org/10.1186/s13567-021-00992-z
  11. Kim MS, Lim TH, Lee DH, Youn HN, Yuk SS, Kim BY, et al. An inactivated oil-emulsion fowl adenovirus serotype 4 vaccine provides broad cross-protection against various serotypes of fowl adenovirus. Vaccine. 2014;32(28):3564-3568. https://doi.org/10.1016/j.vaccine.2014.03.015
  12. Khabiri A, Ghalyanchi-Langeroudi A, Doan PTK, Pakbaz MR, Pakbaten B, Hemmatzadeh F. The complete genome sequence of a new fowl adenovirus (FAdV-4) strain from a recent outbreak in a chicken farm in Iran. Microbiol Resour Announc. 2024;13(4):e00057-24. https://doi.org/10.1128/mra.00057-24
  13. Ishag HZA, Al-Siyabi T, Mohamed M, Al-Rawahi A. Pathology and molecular epidemiology of fowl adenovirus infections. Comp Immunol Microbiol Infect Dis. 2022;86:101831. https://doi.org/10.1016/j.cimid.2022.101831
  14. Hosseini H, Langeroudi AG, Karimi V. Seroprevalence of fowl adenovirus-4 using specific ELISA in poultry farms in Iran. Arch Razi Inst. 2024;79(1):115-121. https://doi.org/10.32598/AMH.79.1.115
  15. Pouladi I, Ghalyanchi Langeroudi A, Hosseini H, Modiri A. Overview of fowl adenovirus serotype 4. Poult Sci. 2024;103(4):103525. https://doi.org/10.1016/j.psj.2024.103525
  16. Liu W, Liu M, Wang S, Tang Z, Liu J, Song S, et al. The development of a novel Fiber-2 subunit vaccine against fowl adenovirus serotype 4 formulated with oil adjuvants. Vaccines. 2024;12(3):263. https://doi.org/10.3390/vaccines12030263
Veterinary and Comparative Biomedical Research

Articles in Press, Corrected Proof
Available Online from 19 August 2026