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Development of a recombinant Newcastle disease virus-vectored vaccine for infectious bronchitis virus variant strains circulating in Egypt

Author:
Abozeid, Hassanein H., Paldurai, Anandan, Varghese, Berin P., Khattar, Sunil K., Afifi, Manal A., Zouelfakkar, Sahar, El-Deeb, Ayman H., El-Kady, Magdy F., Samal, Siba K.
Source:
Veterinary research 2019 v.50 no.1 pp. 12
ISSN:
1297-9716
Subject:
Infectious bronchitis virus, Newcastle disease, Newcastle disease virus, Western blotting, White Leghorn, chicks, fluorescent antibody technique, glycoproteins, infectious bronchitis, live vaccines, poultry industry, protein synthesis, signs and symptoms (animals and humans), vaccination, viral shedding, virulence, viruses, Egypt, Middle East
Abstract:
Infectious bronchitis virus (IBV) causes a major disease problem for the poultry industry worldwide. The currently used live-attenuated vaccines have the tendency to mutate and/or recombine with circulating field strains resulting in the emergence of vaccine-derived variant viruses. In order to circumvent these issues, and to develop a vaccine that is more relevant to Egypt and its neighboring countries, a recombinant avirulent Newcastle disease virus (rNDV) strain LaSota was constructed to express the codon-optimized S glycoprotein of the Egyptian IBV variant strain IBV/Ck/EG/CU/4/2014 belonging to GI-23 lineage, that is prevalent in Egypt and in the Middle East. A wild type and two modified versions of the IBV S protein were expressed individually by rNDV. A high level of S protein expression was detected in vitro by Western blot and immunofluorescence analyses. All rNDV-vectored IBV vaccine candidates were genetically stable, slightly attenuated and showed growth patterns comparable to that of parental rLaSota virus. Single-dose vaccination of 1-day-old SPF White Leghorn chicks with the rNDVs expressing IBV S protein provided significant protection against clinical disease after IBV challenge but did not show reduction in tracheal viral shedding. Single-dose vaccination also provided complete protection against virulent NDV challenge. However, prime-boost vaccination using rNDV expressing the wild type IBV S protein provided better protection, after IBV challenge, against clinical signs and significantly reduced tracheal viral shedding. These results indicate that the NDV-vectored IBV vaccines are promising bivalent vaccine candidates to control both infectious bronchitis and Newcastle disease in Egypt.
Agid:
6306344