IMMUNISATION AGAINST ANTHRAX 347 



The immunisation of animals against anthrax has always 

 been found to be a difficult proceeding. The most usual 

 technique has been to commence with Pasteur's vaccines, and to 

 follow these by careful dosage with virulent cultures. Marchoux 

 in this way produced immunity, and found that the serum of 

 immune animals had a certain degree of protective and curative 

 action. The most successful attempts in this direction have 

 been those of Sclavo and of Sobernheim. The former observer, 

 after trying various animals, came to the conclusion that the 

 ass was the most suitable. He first employed a method similar 

 to that of Marchoux ; later, however, after noting the effects 

 of the serum of an animal so immunised, he commenced the 

 immunisation by injecting 5 to 15 c.c. of this serum along with 

 a slightly attentuated culture of the bacilli. A few days later 

 this was followed up with injections of virulent cultures which 

 could now be periodically introduced for many months, and a 

 high degree of immunity resulted. What was even more 

 important, the serum of such an animal had strongly protective 

 and curative properties. It has been extensively used in the 

 treatment of anthrax in man. In a case of malignant pustule 

 30 to 40 c.c. are injected in quantities of 10 c.c. into the 

 abdominal wall, and if necessary the injection is repeated on the 

 following day. In cases treated by Sclavo himself the serum is 

 alone employed, and its action is. not aided by the excision 

 of the pustule usually practised. The results obtained have been 

 very good, Sclavo, out of 164 cases, had only ten deaths or 

 about a fourth of the ordinary mortality in Italy. Sobernheim 

 independently elaborated an almost identical method of com- 

 bining passive with active immunisation for the obtaining of a 

 powerful anti-serum, and he has used this for the protective 

 inoculation of cattle. The technique is to inject a mixed serum 

 obtained from the ox, the horse, and the sheep, into one side 

 of the neck or into one thigh and the culture (Pasteur's second 

 vaccine) into the other side ; the doses given are for cattle or 

 horses 5 c.c. of serum and 0'5 c.c. culture, and for sheep 4 c.c. 

 of serum and 0*25 c.c. culture. The method has been widely 

 used in Germany and in Brazil, and its originator claims as its 

 advantages simplification of application, in that one operation 

 instead of two is sufficient, less risk of death following the 

 immunisation procedure, and higher degree and more lasting 

 character of the immunity resulting. During the development 

 of active immunity it is likely in every case (see Immunity) that 

 there is a . period of increased susceptibility to the disease. 

 Such a period would be more likely to occur with the Pasteur 



