RIGI and Flavivirus Infections: PRRs relevant to flavivirus infection include Toll-like receptor (TLR), TLR3, and TLR7/8 [22], as well as RIG-I-like receptors (RLRs), including Retinoic acid-Inducible Gene I (RIG-I) and Melanoma Differentiation-Associated gene 5 (MDA5), which are involved in early and late innate immune responses, respectively [19,23,24].