Tetanus Immunization *

Tetanus immunity produced in man by injections of tetanus toxoid is receiving an increasing amount of attention. That man responds to two or three injections of such toxoid-preferably alum-precipitated-with the production of antitoxin has been established firmly by a number of investigators during the past few years. Of the more recent work, that by Bergey and Etris,2 Bergey,' Jones and Moss,6 and Sneath7 may be mentioned. The duration of this immunity has been discussed by Sneath and Kerslake9 and by Bergey and Etris.3 However, the incidence of tetanus is so low that probably years must elapse before the value of immunization can be determined from statistics, and, in the meanwhile, even though man can be immunized, we are confronted with questions which should be answered before we put too much trust in the efficacy of the immunity. This paper reports some results of attempts to answer two of these questions, namely, the amount of antitoxin which we can consider adequate to prevent tetanus following an infection, and the speed of antitoxin response in a sensitized person who has received an injection of toxoid.