The incidence and mortality of diphtheria have been effectively reduced by the extended introduction of immunization against the disease. In the popularization of such a procedure, the fine work of Park and his associates deserves a place as a distinctly outstanding achievement for public health. The procedure has been adopted in the public schools of hundreds of communities. Through these agencies tangible statistical evidence of its benefits has been recorded. The complete effectiveness of the immunization program has been lessened by the difficulty of reaching the preschool child, among which group the highest incidence of diphtheria prevails, and by the imperfections of methods and materials used.
To eradicate diphtheria completely, immunization must become as routine a medical practice for the preschool child as is the administration of orange juice a dietetic measure for the infant. Such custom, however, must be made secure by perfecting methods and materials now available.