192 ACTIVE IMMUNIZATION 



Per cent. Billion per c.c. 



Staphylococcus aureus and albus ... 1 10.0 



Streptococcus hemolyticus 1 8.0 



Gonococcus 1 8.0 



Pneumococcus 1 2.5 



Bacillus typhosus 1 = 8.0 



Bacillus coli 1 4.0 



With different speeds different standards will, of course, be 

 obtained. 



After the strength of the emulsion has been determined the 

 material is diluted to the desired degree with carbolic acid, such that 

 the final content of the latter shall be between 0.25 and 0.5 per cent. 

 This then constitutes the vaccine and keeps practically indefinitely. 

 The manufacturers now furnish this in little ampoules containing the 

 requisite dose. 



Dose and Method of Vaccination. For practical purposes Wright 

 recommends a first injection of 750,000,000 to 1,000,000,000 organ- 

 isms, and double this dose for the second treatment. These injec- 

 tions may be made practically anywhere, where the skin is not bound 

 down tightly. I have thus found the outer aspect of the upper arm, 

 where the skin lies quite loose, a favorable locality. Others inject 

 in the loin, or in the back, in the neighborhood of the shoulder-blade. 

 The injections are, of course, to be made with a sterile syringe, and 

 after having cleansed the area to be injected with soap and water 

 and alcohol, or, as has recently been recommended, after painting 

 with tincture of iodin. The needle puncture is covered with collodion. 



Fearing that the injection of a large dose of organisms may at 

 first be followed by a diminution in the protective substances of the 

 body (negative phase), owing to an interaction between the normal 

 antibacterial substances and the bacterial antigen, and that the indi- 

 vidual may thus be temporarily less resistant to the corresponding 

 infection, Wright has suggested that in persons who are likely to be 

 exposed to typhoid infection soon after the first injection, this should 

 be smaller than usual, and that its effect is to be supplemented later 

 by a correspondingly stronger injection. Whether or not such a 

 danger actually exists in the case of the human being has not yet 

 been demonstrated. In the animal experiments, such a period of 

 diminished resistance apparently does not develop, for Pfeiffer and 

 Friedberger have shown that guinea-pigs which have been vaccinated 



