Abstract: The present invention is directed generally to M1 polypeptides that can be utilized as vaccines and/or antigens for generation of anti-M1 polypeptide antibodies for prophylactic treatment of individuals who are susceptible to infection by influenza virus. The anti-M1 polypeptide antibodies of the invention are useful for treatment of individuals infected with influenza virus, or useful for prophylactic treatment of individuals who are susceptible to infection by influenza virus, or for immune-suppressed individuals who cannot generate an effective antibody response.