Immunostimulating reconstituted influenza virosomes (IRIVs) are a liposomal carrier system. Influenza hemagglutinin and neuraminidase are intercalated into the lipid bilayer and give the IRIVs their fusogenic activity. The system is already registered for human use and allows a specific targetting of antigens to a cellular or a humoral immune response. IRIVs are able to deliver proteins, RNA/DNA, peptides and mimetics to immunocompetent cells.