Quantification of IBDV load in bursal tissue of SPF chickens in the different treatment groups by qRT-PCR.

Viral load in the BF of VP2-BP, C+ and C- groups was quantified 10 days post challenge by qRT-PCR. Chickens (six per group) were vaccinated with three doses of VP2-BP or the commercial IBD vaccine containing inactivated Gumboro (C+) or PBS as negative control (C-). Three untreated not-challenged birds served as control group (Untreated). IBDV RNA loads were determined using a standard curve and individual values expressed as log₁₀ CID₅₀/μl were plotted on the scatter plot shown. Horizontal lines indicate means with error bars.