Liposomal adjuvant compositions

A liposome comprising an external lipid bilayer membrane and an internal compartment, the external membrane comprising:

• a) a quaternary ammonium compound;
• b) a sterol;
• c) a phospholipid;
• and
• d) a glycolipid of formula I:
• wherein, R1 and R2 are independently hydrogen, or a saturated alkyl radical having up to 20 carbon atoms;
• X is —CH2—, —O— or —NH—;
• R2 is hydrogen, or a saturated or unsaturated alkyl radical having up to 20 carbon atoms;
• R3, R4, and R5 are independently hydrogen, —SO42−, —PO42−, —COC1-10 alkyl;
• R6 is L-alanyl, L-alpha-aminobutyl, L-arginyl, L-asparginyl, L-aspartyl, L-cysteinyl, L-glutamyl, L-glycyl, L-histidyl, L-hydroxyprolyl, L-isoleucyl, L-leucyl, L-lysyl, L-methionyl, L-ornithinyl, L-phenyalany, L-prolyl, L-seryl, L-threonyl, L-tyrosyl, L-tryptophanyl, and L-valyl or their D-isomers.