Several viruses bear close evolutionary relationships to TBEV [2] [3] [4] [5] [6] viz. LIV, Spanish sheep encephalomyelitis virus (SSEV), Turkish sheep encephalitis virus (TSEV) and Greek goat encephalitis virus (GGEV). These four lineages have recently been assigned to a single species dubbed Tick-borne encephalitis virus [4] , whose members are primarily associated with ixodic hard-tick vectors. Within this species, the TBEV lineage is further divided into three evolutionary distinct subtypes, the Western European-(W-), the Far Eastern-(FE-) and the Siberian-(S-) TBEV [1, 7] .