While oil-in-water emulsions are excellent adjuvants for influenza vaccines, their efficacy can be improved by additionally including other immunostimulating agent(s) to improve cytokine responses, such as γ-interferon response. Thus a vaccine comprises: (i) an influenza virus antigen (ii) an oil-in-water emulsion adjuvant and (iii) a cytokine-inducing agent, wherein the cytokine inducing agent is an agonist of human TLR4.