Discrepancies in the efficacy of H5 inactivated avian influenza vaccines in specific-pathogen-free chickens against challenge with the Egyptian H5N8 clade 2.3.4.4 Group B virus isolated in 2018
-
Published:2021-08-20
Issue:
Volume:
Page:2131-2141
-
ISSN:2231-0916
-
Container-title:Veterinary World
-
language:en
-
Short-container-title:Vet World
Author:
El-Moeid Amena Abd1ORCID, EL-Deeb Ayman Hany1ORCID, Elsaied Marwa Fathy2ORCID, Soliman Reem Ahamed2ORCID, EL-Safty Mounir Mohamed2ORCID, Hussein Hussein Aly1ORCID
Affiliation:
1. Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt. 2. Central Laboratory for Evaluation of Veterinary Biologics, Abassia, Cairo, Egypt.
Abstract
Background and Aim: Highly pathogenic avian influenza H5N8 virus of clade 2.3.4.4 was newly emerged to Egypt and firstly detected in carcasses of wild birds in November 2016. This study assessed the protection efficacy and virus shedding reduction of three different inactivated avian influenza (AI) H5 (H5N1, H5N2, and H5N3) commercial vaccines against challenge with two newly emerging highly pathogenic AI virus H5N8 Egyptian isolates in specific-pathogen-free (SPF) chicks.
Materials and Methods: 10-day-old SPF chicks (n=260) were divided into 20 groups (n=13). Groups 1-5 were vaccinated through the subcutaneous route (S/C) with 0.5 mL of H5N1 vaccine, Groups 6-10 were vaccinated (S/C) with 0.5 mL of H5N2 vaccine, and Groups 11-15 were vaccinated (S/C) with 0.5 mL of H5N3 vaccine. Positive control groups (16-19) were challenged at 25 and 31 days old (2 and 3 weeks post-vaccination [PV]) using H5N8 clade 2.3.4.4 A/duck/Egypt/ F13666A/2017(H5N8) and H5N8 clade 2.3.4.4 A/chicken/Egypt/18FL6/2018(H5N8). Group 20 was left non-vaccinated as a control. All vaccinated groups were divided and challenged with both viruses at 25 and 31 days of age. The viral challenge dose was 0.1 mL of 106 EID50/0.1 mL titer/chick, and it was administered oronasally. All chicks were kept in isolators for 14 days after each challenge. Sera samples were collected weekly and at 2 weeks post-challenge (PC) to detect a humoral immune response. PC mortalities were recorded daily for 10 days to calculate the protection percentages. Tracheal swabs were collected from the challenged chicks in different groups at 3, 5, 7, and 10 days PC. Kidneys and spleens were collected at 3, 5, 7, and 10 days PC and kept in formalin for histopathological examination to assess lesions and severity scores. Tracheal swabs were inoculated in 10-day-old SPF embryonated chicken eggs for virus titration and to calculate shedding levels.
Results: All studied vaccines displayed 70-100% protection within 10 days PC. Hemagglutination inhibition results from sera samples revealed antibody titers ranging from 0.6 to 5.4 log2 starting at 1-week PV with the highest titers at 4 weeks PV. Challenged SPF chickens exhibited a notable reduction in virus shedding, with an average of 1.5-2 log10, compared to control birds. Various histopathological lesions with different scores were detected.
Conclusion: Our findings suggest that the inadequate virus shedding reduction and protection efficacy of studied vaccines were variable and that the type of vaccine to be used under field conditions should be reconsidered. Study of the variability between the Egyptian old emerged AI (AIV) 2017 H5N8 strains and the new emerging AIV 2018 H5N8 is required to achieve optimal protection and limit the current economic losses.
Funder
Faculty of Veterinary Medicine, Cairo University
Publisher
Veterinary World
Subject
General Veterinary
Reference41 articles.
1. Selim, A.A., Erfan, A.M., Hagag, N., Zanaty, A., Samir, A.H., Samy, M., Abdelhalim, A., Arafa, A.S.A., Soliman, M.A., Shaheen, M. and Ibraheem, E.M. (2017) Highly pathogenic avian influenza virus (H5N8) clade 2.3. 4.4 infection in migratory birds, Egypt. Emerg. Infect. Dis., 23(6): 1048. 2. Kandeil, A., Ahmed Kayed, Y.M., Webby, R.J., McKenzie, P.P., Kayali, G. and Ali, M.A. (2017) Genetic characterization of highly pathogenic avian influenza H5N8 viruses isolated from wild birds in Egypt. J. Gen. Virol., 98(7): 1573. 3. Yehia, N., Naguib, M.M., Li, R., Hagag, N., El-Husseiny, M., Mosaad, Z., Nour, A., Rabea, N., Hasan, W.M., Hassan, M.K. and Harder, T. (2018) Multiple introductions of reassorted highly pathogenic avian influenza viruses (H5N8) clade 2.3. 4.4 b causing outbreaks in wild birds and poultry in Egypt. Infect. Genet. Evol., 58: 56-65. 4. Salaheldin, A.H., Abd El-Hamid, H.S., Elbestawy, A.R., Veits, J., Hafez, H.M., Mettenleiter, T.C. and Abdelwhab, E.M. (2018) Multiple introductions of influenza a (H5N8) virus into poultry, Egypt, 2017. Emerg. Infect. Dis., 24(5): 943. 5. Mady, W., Yehia, N., Elhussieny, M.H., Shalaby, A.G., El Sayed, M.M., Bakry, N.R., Shaaban, A., Arafa, A.S., Mahmoud, A.A.B. and Hassan, W.M. (2019) Genetic characterization of highly pathogenic avian influenza virus (H5N8) in backyard poultry production sector during Mid-2017 to autumn 2018. Hosts Viruses, 6(3): 75.
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|