2. Was ever vaccinated with a licensed or investigational Flavivirus vaccine. Including Japanese encephalitis virus (JEV) vaccine or an investigational Flavivirus vaccine including dengue virus (DENV) or West Nile virus vaccine, or has been diagnosed with an illness caused by a Flavivirus including DENV, West Nile virus (WNV), JEV, St. Louis encephalitis, or tick-borne encephalitis virus (TBEV). Subject's verbal history will suffice.