High potency antibodies, including immunologically active fragments thereof, having high kinetic association rate constants and optional high affinities are disclosed, along with methods for producing such antibodies. The high potency antibodies disclosed herein are of either the neutralizing or non-neutralizing type and have specificity for antigens displayed by microorganisms, especially viruses, as well as antigenic sites present on cancer cells and on various types of toxins, and the products of toxins. Processes for producing high potency neutralizing antibodies and increasing the potency of already existing neutralizing antibodies are also described. Methods of using said antibodies in the prevention and/or treatment of diseases, especially diseases induced or caused by viruses, are disclosed.