532 THE ANTHRAX BACILLUS 



Note. When the serum is inoculated before or immediately after a virulent 

 culture, the rabbit shows no signs of illness but it has acquired no immunity against 

 the bacillus : for, if inoculated later, it succumbs to anthrax after the same lapse 

 of time as control animals. On the other hand, when there has been some delay 

 so that the serum is not given for 7-24 hours after the infection the animal has 

 become sufficiently ill to enable it to acquire, during recovery and with the aid of the 

 serum, a marked resistance to anthrax. 



III. Sclavo undertook a series of experiments which enabled him to pro- 

 duce serums endowed like that of Marchoux with prophylactic and therapeutic 

 properties but devoid of all bactericidal or antitoxic properties. 



(a) Sheep after being first treated with the two vaccines of Pasteur were 

 then repeatedly inoculated with virulent cultures in gradually increasing 

 quantities. A serum was thus obtained which in doses of 2 c.c. protected 

 rabbits against doses of anthrax fatal to animals not so treated. 



(b) Asses are still more useful for the preparation of antianthrax serum. 

 Ottolenghi prepared an ass serum by Sclavo's method which protected 

 guinea-pigs against a very virulent virus provided that it was administered 

 intra-peritoneally 24 hours before the test inoculation. 



(c) It is easy to secure a sero-vaccination in guinea-pigs by inoculating 

 6 c.c. of immunized ass serum sub-cutaneously and 1 c.c. of Pasteur's first 

 vaccine intra-peritoneally. 



IV. Sobernheim, repeating and extending Sclavo's work immunized sheep 

 by inoculating them with 10 c.c. of serum intra-venously and with a culture 

 of anthrax sub-cutaneously : if sheep immunized in this way be repeatedly 

 inoculated with virulent cultures a very active serum is obtained. 



Sobernheim succeeded in conferring a substantial immunity on horses and 

 sheep in 10-12 days. The animals were inoculated with 5 c.c. of serum and 

 0'25-0'5 c.c. of a culture of anthrax sub-cutaneously in different parts of the 

 body. According to Sobernheim the successful use of the serum depends 

 above all in using it in combination with the virus. 



V. Sanfelice prepared a dog serum having very marked prophylactic and 

 therapeutic properties. The dogs were first of all inoculated sub-cutaneously 

 with cultures attenuated by growing them for 5-7 days at a temperature 

 of 37 C. and subsequently with more and more virulent cultures. The 



>rocess of immunization lasted about a month. The serum was then found 

 to be very powerfully prophylactic for rabbits but not for guinea-pigs. It 

 possessed neither bactericidal or antitoxic properties but nevertheless proved 

 of value as a therapeutic agent : in doses of 7 c.c. per 1 kg. of body weight 

 it arrested the infection in rabbits if given within 40 hours of the inoculation 

 of bacilli. If the delay were greater than this death ensued whatever the 

 dose employed. 



In a man infected with anthrax Sanfelice observed that the symptoms 

 abated on the third day after the inoculation of 56 c.c. of serum. 



[Human serum therapy. Immune ass serum prepared by Sclavo's method 

 has been used in the treatment of anthrax in man since 1897 with distinctly 

 encouraging results. 



[The inoculations are administered sub-cutaneously. The first inoculation 

 consists of a dose of antianthrax serum followed the next day by a dose of a broth 

 culture of the second vaccine ; ten days later an inoculation consisting of a mixture 

 of antianthrax serum and virulent anthrax bacilli is given and then at more or less 

 regular intervals of 10 days gradually increasing doses of virulent anthrax bacilli 

 without serum until, when tested on rabbits, it protects these animals from a dose 

 of living virulent bacilli sufficient to kill control rabbits. The ass is bled to the 

 extent of about 150 c.c. after a suitable interval from the last inoculation and the 

 immunity is maintained by the inoculation of young gelatin-broth cultures sub- 

 cutaneously at intervals. 



