74 IMMUNITY 



SINGLE DOSE ONLY 

 Infant, 10 to 30 pounds (under 2 years) 



Mild Moderate Severe Malignant 



2,000 3,000 5,000 



3,000 5,ooo 10,000 10,000 



Child, 30 to 90 pounds (under 15 years) 



3,000 4,000 10,000 10,000 



4,000 10,000 15,000 20,000 



Adults, 90 pounds and over 



3,000 S,ooo 10,000 15,000 



5,000 10,000 20,000 40,000 



Method of Administration 



Intramuscular 



Tetanus Anti-toxin. Tetanus anti-toxin is produced in a man- 

 ner similar to that of diphtheria anti-toxin. As the horse is ex- 

 ceedingly sensitive to tetanus toxin, before the immunizing process 

 is begun, the toxin is attenuated by heat or iodine. 



The an ti- toxin is standardized, as in diphtheria, by testing its 

 potency against the toxin. A guinea pig of 500 grams weight is 

 used, and test toxin is employed of such strength that .01 c.c. will 

 kill the guinea pig in about four days. The United States unit 

 of tetanus an ti- toxin is now the least quantity of an ti- tetanic 

 serum necessary to save the life of a 350-gram guinea pig for 

 ninety-six hours against the official test dose of standard toxin 

 furnished by the Hygienic Laboratory of the Public Health 

 Service. 



The toxin of the tetanus bacillus has such an affinity for nervous 

 tissue that, once it becomes attached, separation is difficult, or 

 even impossible if union has existed for some time. More than 

 this the toxin has a greater affinity for nervous tissue than for its 



