Abstract
Diphtheria is an acute toxin-mediated superficial infection of the respiratory tract or skin caused by the aerobic gram-positive bacillus Corynebacterium diphtheriae. The epidemiology of infection and clinical manifestations of the disease vary in different parts of the world. Historical accounts of diphtheria epidemics have been described in many parts of the world since antiquity. Developed in the late 19th century, the diphtheria antitoxin (DAT) played a pivotal role in the history of public health and vaccinology prior to the advent of the diphtheria-tetanus toxoids and acellular pertussis (DTaP) vaccine. One of the most significant demonstrations of the importance of DAT was its use in the 1925 diphtheria epidemic of Nome, Alaska. Coordinated emergency delivery of this life-saving antitoxin by dog-sled relay in the harshest of conditions has left a profound legacy in the annals of vaccinology and public health. Lead dogs Balto and Togo, and the dog-led antitoxin run of 1925 represent a dynamic illustration of the contribution made by non-human species towards mass immunization in the history of vaccinology. This unique example of cooperative interspecies fellowship and collaboration highlights the importance of the human-animal bond in the one-health initiative.