Vaccination is often considered as an appropriate option in prevention most of poultry viral diseases worldwide. This study was conducted to evaluate effects of current routine vaccination routes (spray, eye-drop and drinking water) of live vaccines against infectious bronchitis (IB) on performance and humoral immune responses of broiler chickens. The results of this study indicated that Vaccination significantly (P<0.05) affects performance of the broiler chickens and effects on weight gain

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... FCR, did not differed significantly among these routes. Immune responses of vaccinated chickens were significantly (P<0.001) differed from those of control chickens. Comparison of various vaccination routes revealed that eye-drop group had the highest antibody titer with the closest range. There were also positive significant (P<0. 01) degrees of correlation among chickens vaccinated with spray and eye-drop, spray and drinking water, eye-drop and drinking water (r = 0.84, r = 0.80 and r = 0.82, respectively). In conclusion, eye-drop method induced the highest antibody titers with the closest range.