Abstract
Ramon 1 , 2 , 3 and his colleagues have applied their method of detoxifying diphtheria toxin with formaldehyde to the detoxification of tetanus toxin. The addition of 0.3 to 0.4% of commercial formaldehyde to tetanus toxin causes detoxification at incubator temperature in about 2 weeks. A tetanus toxin containing 5,000 to 10,000 MLD per cc., for guinea pigs, when detoxified can be injected subcutaneously into guinea pigs weighing 300 to 350 gm., in doses of 5 cc. without giving rise to symptoms of intoxication.
Ramon and his colleagues state that 3 doses of 1 cc. of toxoid injected subcutaneously into guinea pigs at 14 day intervals induce a high degree of immunity.
The purpose of this study was to ascertain the protective power and immunity afforded to guinea pigs by 3 doses of tetanus toxoid. The degree of protection obtained was determined by measuring the neutralizing power of the serum of the immunized guinea pigs when administered to normal guinea pigs combined with 0.1 L+ dose of standard tetanus toxin.
We studied the immunizing effects of 2 toxoids, one No. 6 prepared from a toxin containing 3,000 MLD per cc., and the other, prepared from a toxin containing 10,000 MLD per cc. Titration of the sera of 3 guinea pigs immunized with toxoid No. 6 indicated the presence of 0.2 of a unit of antitoxin per cc. of blood-serum, while titration of the sera of 5 guinea pigs immunized with toxoid No. 7 indicated the presence of 0.5 of a unit of antitoxin per cc. of blood serum.
On the basis of the titrations of the antitoxic content of the sera of the guinea pigs treated with toxoids No. 6 and No. 7, the animals received the following doses of tetanus toxin:
The experiments which form the basis of this report confirm the claims of Ramon and his associates that tetanus toxin can be detoxified with commercial formaldehyde as shown by the absence of symptoms from injections into guinea pigs of 5 cc.
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