FLU-v, a novel peptide vaccine, aims to provide a broad-spectrum response and for that it uses as antigens viral proteins that are conserved throughout the different strains. These proteins are not located on the surface of the influenza virus like NA and HA are, but internally. These antigens are not capable of producing neutralising antibodies but can induce cytotoxic T cell responses and non-neutralising antibodies. When cells are infected with influenza, these internal viral antigens are presented on the surface of infected cells. Vaccination with FLU-v generates a population of T cells and non-neutralising antibodies that can recognise these antigens on the surface of infected cells. On recognition, T cells are activated and secrete Th1 cytokines such as INF-gamma, TNF-alpha, and release granzyme and perforin. Non-neutralising antibodies will activate complement and/or induce cytotoxic responses led by Natural Killer cells (NK cells). These T cells and antibody actions will result in the destruction of infected cells.