Induction of immune response in chicken vaccinated with a plasmid DNA encoding fowl adenovirus 4 hexon gene

A recombinant plasmid pcDNA3.1/V5-His-TOPO.fav4hex (8.5 kb) encoding the hexon gene (2916 bp) of fowl adenovirus 4 was found to express hexon protein in transfected Vero cells as detected by immunoperoxidase test. Vaccination of 3-days old chicken with 50 mg of recombinant plasmid DNA intramuscularly revealed that the vaccinated birds' withstood challenge with 10,000 ID₅₀ of virulent liver passaged FAV4 after 21-days of vaccination while the control (non-vaccinated) birds either died or contracted disease. The field trials of the vaccine exhibited safety and potency. The study reveals that the vaccine could be used as a candidate DNA vaccine to protect the birds against FAV4 infection.