Influenza vaccines with oil-in-water emulsion adjuvants are known. The amount of emulsion adjuvant required for an influenza vaccine can be reduced, thereby allowing more vaccines to be made from a given amount of emulsion, and/or minimizing the amount of emulsion that has to be produced for a given number of vaccine doses. These vaccines can conveniently be made by mixing (i) an oil-in-water emulsion and (ii) an aqueous preparation of an influenza virus antigen. In one aspect, substantially equal volumes of components (i) and (ii) are used in another aspect, an excess volume of component (ii) is used. When using substantially equal volumes, component (ii) has a hemagglutinin concentration of more than 60µg per influenza virus strain per ml. Components (i) and (ii) can be presented in kit form.
