VACCINES IN PROPHYLAXIS OF DISEASE 203 



Vaccination Vaccination against typhoid 

 fever is now a procedure of established worth. 

 Its use began in 1896 when Pfeiffer and Kolle, 

 and independently Wright, demonstrated that 



Bacillus typhosus with faintly stained 

 flagella. (Loeffler's method.) 



persons injected with killed typhoid bacilli de- 

 velop the same antibodies in their blood as are 

 found in recovered cases of typhoid fever. 

 Wright then introduced its use into the English 

 Army and the results led to its introduction 

 into other countries. In 1908 Major Russell of 

 the United States Army was delegated to inves- 

 tigate the subject in all its aspects. He visited 



