Diphtheria morbidity and mortality in the United States has been enviably low in the past ten years.1 Furthermore, there has been, as pointed out by Jordan,2 a naturally declining trend in diphtheria since 1895. The low incidence of clinical diphtheria makes it all the more important to maintain the Schick immunity of the large school population, since it has been shown by Dudley3 and others that the duration of the immunity depends a great deal on natural restimulation of the immune response by exposure to diphtheria environment. In the comparatively diphtheria free environment of American cities this restimulation of the immune response is absent, and therefore one might expect a relapse of immunity to occur more frequently.
During the years 1929 and 1930 we4 reported the successful use of toxoid as an immunizing agent in the preschool child. In a recent retesting of 145 of those
SCHWARTZ AB, JANNEY FR. THE NEED OF REDETERMINING SCHICK NEGATIVENESS IN SCHOOL CHILDREN. JAMA. 1938;110(21):1743-1744. doi:10.1001/jama.1938.02790210023007