ACTIVE IMMUNIZATION AGAINST TETANUS

Abstract

32 subjects were actively immunized against tetanus. Tetanus toxoid (plain), tetanus toxoid to which 0.4% alum was added, and alum-precipitated refined tetanus toxoid were used as antigens. Follow-up titrations showed that 2 doses of alum-precipitated toxoid produced a higher level of antitoxic immunity than 3 injs. of toxoid (plain) or with 0.4% alum added. The loss of antitoxin in all groups, regardless of antigen used, was greatest in the first few mos. The great majority of immunized subjects showed less than 0.1 unit of antitoxin per cc. of blood serum at the end of 9 mos. to a yr. after the primary course of inj. Marked individual variability in antitoxin response was noted. This necessitates the inj. of a "repeat" dose whenever an injury occurs. Within one wk. after inj. of this secondary stimulus there is a remarkable increase in the antitoxin titer. This titer is retained longer than is the case after the primary course of injs.