MANUFACTURE OF VACCINES 735 



ANTHRAX VACCINE. While several methods have been used in vac- 

 cinating against anthrax, probably the most important, at present, 

 is that devised by Pasteur. This method consists in the use of cultures 

 which have been attenuated by growth on artificial culture media at 

 temperatures above the optimum. The inoculation of such attenuated 

 cultures into healthy animals results in active immunization. 



The stock culture of Bad. anthracis is usually obtained from the 

 blood of a typical case of anthrax. The culture is transferred to agar 

 or broth and incubated. Two vaccines are prepared, the first being 

 less active than the second. Vaccine No. i, is made by placing in 

 suspension in sterile, physiological salt solution or other liquid, the 

 anthrax organisms which have been grown at a temperature of 42 for 

 a period of fifteen to twenty days. Vaccine No. 2 consists of a 

 similarly treated culture of Bact. anthracis which has grown at a tem- 

 perature of 42 for ten to fifteen days. Tests of both vaccines for 

 activity and safety are made by animal inoculations. Vaccine No. i 

 should kill white mice but should not cause fatal results in guinea-pigs 

 or rabbits. Vaccine No. 2 should prove fatal for both white mice and 

 guinea-pigs, but not for rabbits. 



Healthy animals are first injected subcutaneously with about i c.c. 

 of vaccine No. i. Several days or a few weeks after the application of 

 vaccine No. i, the second vaccine is injected. A severe reaction and 

 sometimes death follows the use of the vaccine. Accidents of this kind 

 have resulted from careless methods employed in standardizing and 

 administering the vaccine. The most important objection to Pasteur's 

 anthrax vaccine is due to the danger involved in the use of the 

 living, attenuated anthrax organisms. 



Scalvo* advocates the use of the serum from animals actively im- 

 munized to anthrax. This method may be employed either in the 

 form of the immune serum alone, or the immune serum and anthrax 

 culture simultaneously. 



Eichhorn f advises the use of antianthrax serum for curative 

 purposes, and the simultaneous treatment with antiserum and a care- 

 fully standardized spore vaccine as a preventive. When vaccine alone 

 is to be employed Eichhorn prefers the spore vaccine rather than the 

 ordinary Pasteur vaccine. 



* Scalvo, CentralbL f. Bakt., 1899, 26, p. 425. 

 f Eichhorn, Bull. No. 340, U. S. Dept. of Agr. 



