Combined H5ND inactivated vaccine protects chickens against challenge by different clades of highly pathogenic avian influenza viruses subtype H5 and virulent Newcastle disease virus.

Autor: Ali A; Department of Poultry Diseases, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt., Safwat M; Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Dokki, Giza 12618, Egypt., Kilany WH; Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Dokki, Giza 12618, Egypt., Nagy A; Department of Virology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt.; Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, 20742, USA., Shehata AA; Department of Avian and Rabbit Diseases, Faculty of Veterinary Medicine, University of Sadat City, Menoufia 22857, Egypt., El-Abideen MAZ; Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Dokki, Giza 12618, Egypt., Dahshan AM; Department of Poultry Diseases, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt., Arafa AA; Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Dokki, Giza 12618, Egypt.
Jazyk: angličtina
Zdroj: Veterinary world [Vet World] 2019 Jan; Vol. 12 (1), pp. 97-105. Date of Electronic Publication: 2019 Jan 01.
DOI: 10.14202/vetworld.2019.97-105
Abstrakt: Aim: The aim of the current study was to evaluate the efficacy of a trivalent-inactivated oil-emulsion vaccine against challenge by different clades highly pathogenic avian influenza (HPAI) viruses including HPAI-H5N8 and the virulent genotype VII Newcastle disease virus (NDV) (vNDV).
Materials and Methods: The vaccine studied herein is composed of reassortant AI viruses rgA/Chicken/Egypt/ME1010/2016 (clade 2.2.1.1), H5N1 rgA/Chicken/Egypt/RG-173CAL/2017 (clade 2.2.1.2), and "NDV" (LaSota NDV/CK/Egypt/11478AF/11); all used at a concentration of 10 8 EID 50 /bird and mixed with Montanide-ISA70 oil adjuvant. Two-week-old specific pathogen free (SPF) chickens were immunized subcutaneously with 0.5 ml of the vaccine, and hemagglutination inhibition (HI) antibody titers were monitored weekly. The intranasal challenge was conducted 4 weeks post-vaccination (PV) using 10 6 EID 50 /0.1 ml of the different virulent HPAI-H5N1 viruses representing clades 2.2.1, 2.2.1.1, 2.2.1.2, 2.3.4.4b-H5N8, and the vNDV.
Results: The vaccine induced HI antibody titers of >6log 2 against both H5N1 and NDV viruses at 2 weeks PV. Clinical protection against all HPAI H5N1 viruses and vNDV was 100%, except for HPAI H5N1 clade-2.2.1 and HPAI H5N8 clade-2.3.4.4b viruses that showed 93.3% protection. Challenged SPF chickens showed significant decreases in the virus shedding titers up to <3log 10 compared to challenge control chickens. No virus shedding was detected 6 "days post-challenge" in all vaccinated challenged groups.
Conclusion: Our results indicate that the trivalent H5ND vaccine provides significant clinical protection against different clades of the HPAI viruses including the newly emerging H5N8 HPAI virus. Availability of such potent multivalent oil-emulsion vaccine offers an effective tool against HPAI control in endemic countries and promises simpler vaccination programs.
Databáze: MEDLINE
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