Studies on diphtheria toxin and its reaction with antitoxin

It has been customary for the recipient of this award to give a resume of his own work.2 I hope that it will not be considered inappropriate if I preface this paper with a few remarks of a more general nature. Since the discovery of diphtheria toxin by Roux and Yersin in 1888 and the discovery of antitoxin two years later by von Behring and Kitasato a vast amount of literature has accumulated and the diphtheria problem may well be considered as a classical problem in bacteriology and immunity. Thus, diphtheria toxin has be-come a model to which the nature and behavior of other bacterial toxins have been related and until about 1925, the diphtheria toxin-antitoxin reaction served as a prototype to which other antigen-antibody systems were compared. However, during the decade which followed the introduction of formol toxoid and the flocculation reaction by Georges Ramon, relatively little progress was made and I think that a notable shift of interest away from the diphtheria problem became evident during that period. It is interesting to examine some of the reasons for this change of attitude. Probably there were many who regarded the diphtheria problem as solved because the disease was no longer a leading 1 Read before the Forty-second Meeting of the Society of American Bacteriol-ogists at Baltimore, Maryland, following the presentation of the Eli Lilly an