Evaluation of t
Evaluation of the Protection conferred by heterologous attenuated live infectious bronchitis viruses againest an Egyptian variant IBV [EG/1212B]
Ali Zanaty1; Abdel-satarArafa1*.Abdallah Selim1.Mohamed Khalifa Hassan1.Magdi Fathey El-Kady2*
1Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, P.O.
Box 264-Dokki, Giza-12618, Egypt.
2Department of Poultry Diseases, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt.
Abstract: Molecular analysis of recent field infectious bronchitis viruses (IBV) isolates in Egypt during last two years has revealed that the most frequent isolates were related to variants IBV represented in this study by EG/1212B which placed in the same group with Israeli virus IS/885/00-like strains. The present study investigated the protection provided by four vaccination regimes using commercial live vaccines against challenge with EG/1212B virus in SPF chickens. Protection efficacy was evaluated by mortalities, clinical signs, ciliostasis test, rRT-PCR and ELISA. None of the tested vaccination regimes was able to confer significant protection against challenge with EG/1212B. The highest protection rate was afforded by using [H120 -D274] at 1 day old and 4/91 at 14 day old that provided only 42.5% cilia protection after challenge with EG/1212B virus. It is recommended to monitor evolving IBV strains and to prepare an autogenous vaccine from this variant to help in controlling the disease in Egypt.
[Zanaty A, Arafa A, Selim A, Hassan MK, El-Kady MF. Evaluation of the Protection conferred by heterologousattenuated live infectious bronchitis viruses againest an Egyptian variant IBV [EG/1212B]. J Am Sci2013;9(6):599-606] (ISSN: 1545-1003). http://www.jofamericanscience.org. 76
Keywords: Ciliostasis; cross-protection; heterologous; infection bronchitis virus; protectotypes; variant strain. Full Text 76