It is generally admitted that diphtheria is less common in children who have had their tonsils and adenoids removed than in those who have not undergone such an operation. Several explanations have been offered: (1) that removal of the tonsils and adenoids influences the humoral immunity against diphtheria; (2) that it eliminates the portal of entry of the diphtheria bacilli, and (3) that the tonsils offer a fertile soil for the growth of diphtheria bacilli.
Schick and Topper1 performed Schick tests on children before tonsillectomy and adenoidectomy and again six months after operation. Their results were striking and would indicate that the decrease in diphtheria in tonsillectomized patients is due to the acquisition of humoral immunity, if the Schick test is used as a measure of immunity against diphtheria. They reported observations on 100 children between 1 and 12 years of age who had a positive Schick reaction before