Abstract: The invention provides a novel vehicle for vaccination, in particular peptide vaccination. The new vehicle has been termed an exosome. Exosomes are vesicles derived from MHC class II enriched compartments in antigen presenting cells. The exosomes possess MHC II and/or MHC I molecules at their surface and possibly peptides derived from processed antigens in said MHC's. Thus the exosome is a perfect vaccination vehicle in that it presents the peptide in a natural setting. The peptides present in the exosome in the MHC molecule may be processed by the antigen presenting cell from which the exosome is derived. Empty MHC molecules on exosomes may also be loaded with peptides afterwards.