The purpose of this human immune physiology study is to use TBEV vaccine as a model neoantigen to investigate immune readouts after antigen targeting. The collection of adverse event or safety data is therefore not relevant to the study objectives and there will be no systematic collection of safety data, other than those required for a Risk Assessed "Type A" CTIMP (SUSAR reporting to MHRA/REC/Concerned Investigators, Annual List of Suspected Serious Adverse Reactions as part of the Annual Safety Report/Development Safety Update Report).