482 INFECTION AND RESISTANCE 



forth as briefly as possible the methods employed in prophylactically 

 immunizing man against this disease in which this procedure has 

 been most commonly attempted. 



PROPHYLACTIC IMMUNIZATION IN TYPHOID FEVER 



The first attempt to inoculate human beings with typhoid bacilli 

 with the intention of producing prophylactic active immunization 

 was probably that made by Pfeiffer and Kolle 84 in 1896. During 

 the same year also Wright 85 made similar studies in England, and 

 soon after this he reported upon the development of antibodies in the 

 blood of 17 people inoculated with typhoid. By these studies it was 

 shown that human beings could be inoculated with dead typhoid 

 bacilli without danger, and this logically led to the attempt to vac- 

 cinate human beings on a large scale. 



It is hardly necessary to dwell upon the desirability of such a 

 procedure. From tables recently published by Russell 86 we take the 

 information that, in our own Spanish-American war, 20,738 cases 

 of typhoid with 1,580 deaths occurred in a total enlistment of 107,- 

 973. In this entire war 243 men were killed in action or died of 

 their wounds, while almost 7 times as many died of typhoid fever. 

 In the British army during the Boer war there were over 75,000 

 cases of typhoid in 380,000 men, and in the Russian army during the 

 Russo-Japanese war over 17,000 cases of typhoid occurred, over half 

 as many as the number of men killed in action. Such appalling fig- 

 ures leave no possible doubt as to the desirability of prophylactic im- 

 munization in armies, and there can be little question that typhoid 

 fever is sufficiently prevalent in many parts of the civilized world to 

 encourage prophylactic immunization of individuals, even when not 

 living under the especially dangerous conditions of camps. 



Following the preliminary studies of Pfeiffer and Kolle and of 

 Wright extensive practical studies of vaccination were made in the 

 German colonial army during the Herrero war, and by British 

 bacteriologists during the Boer war. Leishmann 87 also studied care- 

 fully the results of vaccination among regiments of the British army 

 in India. 



The vaccine employed by Wright and his associates in England 

 consisted of broth cultures of a typhoid bacillus killed by exposure to 

 53 C., and by the further addition of 0.4 per cent, of lysol. The 

 German vaccine consisted of emulsified agar cultures similarly killed. 



The results obtained with these vaccines, although encouraging, 



84 Pfeiffer and Kolle. Deutsche med. Woch., 22, 1896, p. 735. 



85 Wright. Brit. Med. J., Jan., 1897, p. 256. 



86 Russell. Amer. J. of Med. Sciences, Dec., 1913, Vol. 146. 



87 Leishmann. Glasgow Med. Journ., 1912, Vol. 77, p. 408, cited from 

 Russell. 



