96o CONTROL OF BIOLOGICAL PRODUCTS 



ANTI-DYSENTERIC SERUM 



At the present time the standardization of this preparation leaves much to be 

 desired. The requirement that the serum shall be at least as active as the control 

 serum in agglutinating the several types of the dysentery organism is recognized as 

 being very untrustworthy. Tests designed to show the antitoxic content of the prep- 

 arations are more promising though it cannot be said that these are on a substantial 

 basis at present. These latter tests are applicable only to the titration of antisera 

 for the Shiga group of organisms. The subject is complicated by the fact that this 

 organism appears to produce a soluble exotoxin and an endotoxin liberated by lysis of 

 the organism. These toxins act differently, the former affecting chiefly the central 

 nervous system, the latter chiefly the intestinal tract. 



Anti-dysenteric serum is being studied at the present time by the Serums Com- 

 mittee of the League of Nations, and it is forecast that in due time a standard anti- 

 toxin will be distributed for use as a standard control in toxin-antitoxin neutralization 

 tests. 



BACTERIAL VACCINES 



The only preparations of this class subjected to official testing are those made from 

 the typhoid and paratyphoid "A" and "B" organisms. 



ANTI-ENTERIC VACCINES 



Bacterial vaccines made from the typhoid and the paratyphoid organisms probably 

 are far from uniform as prepared by different producers or by the same producer at 

 different times. It is probable, however, that for practical purposes a sufi&ciently uni- 

 form material is secured when the same procedure is followed in making different 

 batches. Since we do not know the exact mechanism by which typhoid vaccine serves 

 as a prophylactic agent it is not possible to apply any thoroughly satisfactory stand- 

 ardization procedure. 



The method in use in the United States^ compares the agglutinin production in 

 rabbits of the products under test with that of a standard control vaccine. 



MISCELLANEOUS PREPARATIONS 

 DIPHTHERIA TOXIN FOR THE SCHICK TEST 



This is distributed in packages containing not over one hundred human doses, 

 each human test dose containing 1/50 or 1/40 of a minimum lethal dose for guinea 

 pigs. The human dose is diluted to o.i or 0.2 cc. for use, according as it contains 1/50 

 or 1/40 M.L.D. In testing the material the toxin is diluted as for human use, and 

 forty or fifty human doses, depending upon the t\Toe of package, are given, sub- 

 cutaneously, to guinea pigs weighing about 250-80 gm. At least 75 per cent of these 

 guinea pigs should die between the sixtieth and ninety-sixth hour with the usual le- 

 sions of diphtheria toxin poisoning. Table VIII shows a typical protocol of the test 

 on a satisfactory commercial preparation. 



TOXIN-ANTITOXIN MIXTURE 



Requirements for this preparation are intended to insure as nearly as possible a 

 preparation sufficiently potent to give immunity when used on human beings but not 



' McCoy, G. W.: Hygienic Laboratory Bull. no. 191 7. 



