﻿418 STEONG. 



immunity, it is not issued for human inoculation. No method of 

 standardizing the small amount of anti-endotoxin which the prophylactic 

 will give rise to in animals has been found to be either practicable or 

 of value. During the period of the epidemic the prophylactic was man- 

 ufactured and used in large quantities and a sufficient supply was kept 

 on hand for emergencies. 



EFFICIENCY OF THE PROPHYLACTIC. 



I called attention to the fact in my previous publications on the 

 subject of protective inoculation against Asiatic cholera, that animals 

 could invariably be protected against a subsequent cholera infection with 

 even multiple lethal closes of the organism as the result of a single 

 inoculation of this prophylactic, in doses of from 1 to 5 cubic centi- 

 meters: and that in addition agglutinative and bactericidal substances 

 became developed in considerable quantities in the blood sera of such 

 animals. However, the antitoxic value of these sera was only moderate. 

 It was also demonstrated that the antibodies which developed in the 

 blood of individuals after inoculation with the prophylactic were iden- 

 tical with those which were encountered in patients convalescent from 

 cholera, and, in addition, that these immunizing substances were fre- 

 quently present in greater amounts after vaccination than after a natural 

 attack of the disease. Moreover, it was shown that animals which con- 

 tained these same antibodies in sufficient quantities in their sera were 

 also invariably immune to cholera infection, the amount of the immune 

 bodies in the serum being proportional to the degree of immunity to 

 infection possessed by the animal. 



"From a single intravenous inoculation of rabbits with an amount 

 of the prophylactic containing the receptors extracted from 2 oesen of 

 a virulent cholera organism, sera were obtained which showed an aggluti- 

 native value of from 1 : 300 to 1 : 600, and a bactericidal one of from 

 0.1 to 0.08 milligram, while from a similar inoculation of the receptors 

 extracted from 12 oesen of the same strain, sera resulted showing aggluti- 

 native values of from 1 : 600 to 1 : 1,000 and bactericidal values of 

 0.08 to 0.04 milligram. From a single intravenous inoculation of \ 

 oese of a living agar culture of this same cholera strain, sera were 

 obtained with an agglunative value from 1 : 400 to 1 : 800 and a 

 bactericidal one of from about 0.1 to 0.06 milligram. 



It is important to observe that 0.5 oese of the living organism gave 

 rise to sera of almost the same value as did the receptors which could 

 be extracted from 2 oesen of the bacteria, but that the receptors extracted 

 from 12 oesen of the organism furnished sera of far greater value. The 

 best antitoxic serum which was produced following a single intravenous 

 inoculation of the prophylactic was found not to be able to neiitralize 

 above four lethal doses of the cholera endotoxin. 



