Combinations of adjuvants for immunization and vaccines.

A combination of adjuvants comprising: * a first adjuvant component which is a halide of quaternary ammonium hydrocarbon of formula NR1R2R3R4-hal, wherein R1 and R2 are each independently a lower alkyl containing from 1 to 3 carbon atoms, R3 and R4 is each independently a hydrocarbon group containing from 12 to 20 carbon atoms, preferably from 14 to 18 carbon atoms, and hal is a halogen atom, and * a second component hydrophobic adjuvant selected from the group consisting of: a monophosphoryl lipid, trehalose dibehenate, sorbitan derivative and triterpenoid saponin.