A centennial review; the 1890 tetanus antitoxin paper of von Behring and Kitasato and the related developments.

The significance of the 1890 tetanus antitoxin paper by von Behring and Kitasato in the development of a new discipline, immunology, is reviewed. The possible reasons why Kitasato lost the first Nobel Prize for medicine to von Behring are presented. These are as follows: (1) The Nobel selection committee literally interpreted Alfred Nobel's will to award the prize to "the person who has made the most important discovery." (2) In the late 19th century, diphtheria was a serious contagious disease which claimed many thousands of lives in the Europe and America; and von Behring's solely authored paper on diphtheria antitoxin clinched the award for him. (3) The merit of tetanus antitoxin to humans, which was the focal point of the 1890 paper on tetanus antitoxin jointly authored by von Behring and Kitasato, was not recognized at the time of the award in 1901; it became apparent only during the First World War.