MF59® is Novartis' proprietary adjuvant that is added to influenza vaccines to help stimulate the human body's immune response through production of CD4 memory cells. MF59, is the first oil-in-water influenza vaccine adjuvant to be commercialized in combination with a seasonal influenza virus vaccine. Adjuvanted vaccines combined with MF59 augment the breadth of immune response compared with non-adjuvanted vaccines.