Disclosed is the use of an antigen or antigenic preparation, in combination with an adjuvant which adjuvant comprises an immunologically active saponin fraction derived from the bark of Quillaja Saponaria Molina presented in the form of a liposome and a lipopolysaccharide wherein said saponin fraction and said lipopolysaccharide are both present at a level of between 1 and 30 mug, in the preparation of an immunogenic composition for vaccination of humans.
