Lower IFN-α, IL-12 (p70), and IL-15 levels measured 24 hours and 48 hours after in vitro stimulation of PBMCs indicate a weaker innate immune response early after TBEV contact, whereas higher expression of IL-6 and TNF-α at 6 days suggests a more extensive inflammatory response in the late stages of TBEV encounter in VBT patients compared to unvaccinated TBE patients. This evidence concerns the gene IL15 and tick-borne encephalitis.