The invention relates to an immunogenic composition comprising influenza virus antigens derived from at least 5 influenza virus strains and one or more compounds of formula (I) or physiologically acceptable salts or esters thereof: wherein: R1 represents hydrogen or C1-6 alkyl； R2 represents C1-6 alkyl； and R3 represents C1-6 alkyl. The invention also relates to methods of preparing the immunogenic composition, to pharmaceutical and vaccine compositions comprising the immunogenic composition and to use of the immunogenic, pharmaceutical and vaccine compositions for preventing influenza virus infection.
