Development of a rapid, sensitive, and reproducible method for the ex-vivo detection, quantification and characterization of cell-mediated immune responses induced by natural infection or vaccination. This method will hopefully enable us to replace the applied laborious and expensive methodologies thereby increasing the applicability of these types of immune monitoring methods in large (field) trials. This simplified method will allow for direct detection of the parameters correlating with (long-term) protection in the blood tube, without prior cell isolation and/or technically challenging sample storage,