A human polyclonal antibody having an antibacterial and/or antiviral activity with a desired titer and a wide spectrum; and human polyclonal antibody composition for preventing and treating infections which contain this antibody. The human polyclonal antibody composition for preventing or treating infections contain the human polyclonal antibody which is obtained by administering as immunogen a bacterium and/or a virus or a component of the bacterium and/or the virus to a non-human animal having a human antibody gene locus and has an antibody titer against the bacterium and/or the virus exceeding that of human pool plasma.