I Q2 PRACTICAL METHODS IN IMMUNITY 



M. mclilensis, 700 and 1400. 



B. coli, 1 6 and 240. 



B. typhosus (treatment) 100 and 250. 



B. typhosus (prophylaxis) 500 and 1000. 



B. pyocyanens, 34 and 1000. 



B. pneumonia, 44. 



Staphylococci, 150 and 900. 



B. tuberculosis, Hoooo to /^oo rag. 



Sensitized Vaccines. These are prepared by treating the bacteria 

 with the specific serum and cause less reaction than ordinary vaccines. 

 To prepare them the bacterial growth is treated with its antiserum 

 for three hours, thrown down in the centrifuge and the supernatant 

 serum removed. After washing in salt solution they are emulsified in 

 salt solution and killed at a temperature of 56C. for one hour. Besredka 

 has used living sensitized bacteria in typhoid. 



The question of the best method of preparing vaccines for prophylactic use is still 

 unsettled. The greatest difficulty has been experienced in making vaccines of the 

 Shiga bacillus on account of the great toxicity of such preparations. 



Thompson has recently carried out some very important experiments at the 

 Lister Institute. 



He worked with vaccines heated to s6C. for one hour using ordinary methods as 

 well as organisms sensitized by treatment with specific serum. In another series 

 of vaccines he sterilized ordinary cultures as well as sensitized ones with 0.5% 

 carbolic acid in normal saline. He found that sterilfzation by heat not only destroyed 

 much of the immunizing power of the vaccines, but that such vaccines, whether of 

 ordinary bacterial emulsions or of sensitized organisms, showed great toxicity upon 

 their being injected and the heated sensitized ones were somewhat more toxic than 

 the nonsensitized organisms. Dean has used "eusol" for Shiga vaccines. 



On the whole it would seem that sterilization with %% carbolic or Y% trikresol, 

 using ordinary bacterial emulsions, is better than other methods. 



Of course living organisms subjected to their specific serum have been recom- 

 mended in the case of typhoid but such methods are certainly not devoid of danger 

 and are not to be recommended for the present. 



ANAPHYLAXIS 



This is a term which indicates the opposite of prophylaxis. It was 

 noted that after a period of incubation of at least ten days a second 

 injection of horse serum produced symptoms of respiratory embarrass- 

 ment, convulsions and, at times, death. The primary injection had 

 during the period of incubation sensitized the cells to this particular 

 proteid. Extremely small amounts of serum will sensitize (o.oooi c.c.). 

 For anaphylaxis production much larger amounts are required; from 



