Abstract
This two part paper is a selective review of developments of greatest significance to practicing physicians. Among the topics considered in part 1 are the immunologic mechanisms of the common atopic allergic diseases (asthma, allergic rhinitis, infantile eczema), the immunoglobulins of human serum and their concentrations in infancy, and two significant immunohematologic developments: intra-uterine transfusion in hemolytic disease and suppression of immune response by 6-mercaptopurine.