Archaeal lipid adjuvants are synthesized by chemically coupling various carbohydrates or anionic polar groups to the free hydroxyl(s) of archaeal lipid cores. Chemically stable lipid cores such as saturated archaeol and caldarchaeol are obtained from appropriate Archaea. Archaeosome lipid vesicles are formulated from the synthetic lipids selected to serve as antigen carriers that target antigen-presenting cells and promote an appropriate immune response to the antigen.