Summary of the results obtained from immunized chickens challenged with IBDV.

1Route of vaccine administration was shown as O: oral (via oral gavage), P: parenteral (intramuscularly) and X: no vaccination.2BF/BW ratio was calculated by the bursal weight (g) divided by body weight (kg) and presented as the mean values that were presented by different letters (A and B) are significantly different (p3The bursa lesion score was calculated according to previously described system [33].4Chickens with antigen were detected by sandwich ELISA.5Pichia: freeze-dried and inactivated intact P. pastoris cells. Resuspended in 1 ml drinking water.6Oral adjuvant is a mixture of NaF salt (100 mg/kg chicken weight) and 50 µg CpG oligodeoxynucleotide (CpG ODN).7The administered dosage was according to the manufacture's instructions (Lohmann Animal Health, Cuxhaven, Germany).