Prophylactic treatment with Toll-like receptor ligands enhances host immunity to avian influenza virus in chickens

► Treatment of chickens with TLR ligands reduced shedding of avian influenza virus. ► Treatment with poly I:C resulted in a 5 log decrease in virus shedding. ► CpG treatment reduced virus shedding by more than 3 log. ► LPS treatment also reduced virus shedding by ∼2 log. ► Immunity correlated with IFN-γ, IFN-α and IL-8 expression.