On the Susceptibility to Diphtheria (Schick Test Positive) with Reference to the Inheritance of Blood Groups

Abstract

Abstract By means of the Schick reaction, we were able to distinguish, among human beings, those susceptible to diphtheria from the immune. The blood of the individuals having a negative Schick reaction contains normal antitoxin, and these are resistant to the infection. The origin of normal antitoxin has not been heretofore explained. Most investigators regard them as representing an acquired immunity. However, we meet with Schick negative individuals who have not had diphtheria. In these cases, the authors suppose that we are dealing with the effect of unrevealed infections. The following data seem to support this opinion. The countrymen are more often susceptible than town dwellers. The poor are more often immune than the rich. Children are more susceptible than grown-ups, girls more than boys. The authors explain this greater immunity of the poor and boys by their being more exposed to infection.