Although we cannot address what happens during later stages (evolution and maintenance of memory CD8+ T cells) in the context of type I IFN blockade and virulent WNV-NY infection because of complete lethality in the model, kinetic studies are planned with the attenuated WNV-MAD strain and MAR1-5A3 to determine how and when type I IFN signaling affects the transition to and establishment of memory phenotypes. This evidence concerns the gene CD8A and infection.