The genus Flavivirus contains approximately 70 viruses, and the major flaviviruses that cause human diseases are yellow fever virus (YFV), dengue virus (DV), West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus [1]. The flaviviral particles contain single-stranded, positive-sensed RNA genome packaged within an icosahedral capsid formed by the capsid protein. The genome-containing capsid is surrounded by a host-derived lipid bilayer bearing dimers of the viral envelope protein and the membrane protein. The sizes of flavivirus virions are approximately 37–50 nm. Thus, the antigenic, genetic, and three-dimensional structures of all the flaviviruses are similar to each other.