VACCINATION AGAINST TUBERCULOSIS 75 



ment of the Unites States supply the vaccine gratis to stock raisers 

 and others. 



A valuable anti bacterial serum is used also as a therapeutic 

 measure-anthrax infection. 



Vaccination Against Black-leg or Quarter-evil. 



Quarter-evil, or Rauschbrand, is due to a specific bacillus. Vac- 

 cination against this disease may be accomplished by inoculating 

 with a powder consisting of dried muscle from the affected part of 

 infected animal. There are two vaccines, No i, and No 2. The 

 first is prepared by heating (and thus attenuating) the bacilli up to 

 103 C. The second is prepared by raising the temperature up to 

 93 C. These vaccines are given at a short time apart, and the 

 immunity is effective. The method is valuable to stockmen. 



Vaccination Against Tuberculosis. 



It is possible to vaccinate animals against tuberculosis by the 

 use of attenuated tubercle bacilli. To accomplish this, the sole 

 requisite is to so weaken the bacilli used to immunize, that there is 

 not any likelihood of causing any lesion. By long cultivation on 

 culture media bacilli are so attenuated that they cannot cause harm 

 to a guinea pig, even if repeatedly injected. Guinea pigs may, 

 when properly treated, live long after inoculation with virulent 

 bovine bacilli, but at no time do they become wholly immune; 

 cows may be immunized against bovine bacilli by inoculating them 

 with weak human cultures. Koch's new tuberculin, made by 

 grinding to a powder the dried bodies of tubercle bacilli, is also able 

 to set up an immunity in animals, and to a limited extent in man. 

 It is used in several large sanitariums devoted to the cure of tuber- 

 culosis, as a therapeutic agent. Those using it claim that it 

 immunizes the individual and thus increases his resisting powers. 

 Webb of Colorado claims to have produced immunity in monkeys 

 and children by injecting exceedingly small numbers of living 

 bacilli, i, 2, 4, 8, 12, 18, 25, etc. 



