TLR7 and infection: Therefore, we used different TLR agonists: poly I:C (dsRNA) for a representative IFN-α response through TLR3/RIG-I, and TLR7/8 by two formulae of influenza (ssRNA) vaccine (antigen); whole-virion influenza vaccine (representing the natural response to infection); and split-virion influenza vaccine (representing the response to seasonal vaccination using TIV).