Needle inoculation of the virus into mice resulted in an increased expression of TLR3 and Th1 cytokines (IFN-γ and IL2) whereas infection by mosquito bite elicited a Th2 cytokine response with an increase in IL4 and a reduction observed in TLR3, IFN-γ and IL2 (53). This evidence concerns the gene IL2 and infection.