IMMUNISATION AGAINST ANTHRAX 349 



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 for the obtaining of the anti-serum. 

 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 attenuated culture of 

 the bacilli. A few days later this was followed up with injec- 

 tions 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 combining passive with active immunisation 

 for the obtaining of a powerful anti-serum, and he has used the 

 same principle 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 

 - 5 c.c. culture, and for sheep 4 c.c. of serum and - 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 method than with the 

 Sobernheim procedure, where the presence in the animal's body 

 of the protective serum might tide it over the stage when the 

 action of the vaccine was lowering its resistance. 



