Described is a method for preparing a liquid vaccine combination comprising at least: - aluminum oxide hydroxide (AlOOH), - one hepatitis B surface antigen (HBsAg), - one Haemophilus influenzae type b (Hib) antigen consisting of capsular polysaccharide conjugated to a carrier protein, in which the hepatitis B surface antigen is kept adsorbed on AlOOH, whereas the Hib antigen is kept nonadsorbed, wherein: - the hepatitis B surface antigen is adsorbed onto AlOOH in order to obtain an AlOOH/HBsAg complex, - said AlOOH/HBsAg complex is mixed with the Hib antigen in the presence of cationic amino acids at a concentration of at least 100 mg/l and of phosphate ions at a concentration of 35 to 45 mMol/l.
