In this review, three questions relating to the prevention of diphtheria will be critically discussed:
What is the best statistical method of checking the efficiency of active immunization against diphtheria?
What are the severity and the clinical typology of diphtheria which occurs in previously immunized children?
How may the limits of antitoxin treatment of toxic diphtheria be overcome by nonspecific preventive therapy?
STATISTICAL METHODS
Method Presenting Morbidity Curves Before and After the Introduction of Immunization.—Among the statistical methods used to check the efficiency of immunization there is one which is often applied in an uncritical fashion. It consists of obtaining local statistics on diphtheria morbidity before and after the introduction of active immunization in a given community. In order to use this method scientifically the natural trend of diphtheria morbidity in a certain area must be followed over a long period. In chart 1 diphtheria morbidity