The present invention is directed generally to Ml polypeptides that can be utilized as vaccines and/or antigens for generation of anti Ml polypeptide antibodies for prophylactic treatment of individuals who are susceptible to infection by influenza virus. The anti Ml 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.