THERAPEUTIC IMMUNIZATION IN MAN 485 



were not as striking as had been hoped. Russell 88 summarizes the 

 earlier attempts by stating that the morbidity was reduced to about 

 one half among vaccinated persons with a slightly greater reduction 

 of mortality. The last-named writer also attributes the early fail- 

 ures to the overheating of the vaccines with a consequent reduction 

 of their antigenic properties, and to timidity in their administration 

 resulting from Wright's fear of a negative phase. Russell, of the 

 United States Army Medical Corps, made a most extensive study of 

 typhoid vaccination in this country. After careful consideration of 

 the methods of others he produces his vaccines as follows : A single 

 strain of typhoid bacilli is used (culture Rawlings obtained from 

 England), and this is grown on agar in Kolle flasks for 18 hours. 

 The purity of the culture is tested out both morphologically and by 

 transplantation upon the double sugar media devised by Russell. 

 Agglutination tests are also made. After 18 hours the growth is 

 washed off in small quantities of salt solution and the emulsion heated 

 in a water bath for one hour at 53 C. ; it is then diluted with sterile 

 salt solution to a concentration of one billion bacteria to a cubic 

 centimeter. Then 0.25 per cent, of tricresol is added. Before use 

 the safety of the vaccine is ascertained both by aerobic and anaerobic 

 cultivation and by the injection into mice and guinea pigs of consid- 

 erable quantities for the exclusion of possible tetanus contamination. 

 The efficiency of the vaccine is then tested by injecting rabbits with 

 three doses at 10-day intervals, and determining the resulting ag- 

 glutinating power. 



With these vaccines under the direction of the United States 

 Army Medical Corps the troops mobilized in Texas, California, and 

 along the Mexican border were treated. Compulsory vaccination was 

 established in March, 1911, and the results as reported by Russell 

 have fully justified the measure. The following table taken from 

 Russell's paper will illustrate the results obtained : 



Typhoid Fever. Officers and Enlisted Men, United States Army 



Paratyphoid fever included in figures for 1908, but excluded in other years. Cases paratyphoid 

 1909, 3; 1910, 3; 1911, 2; 1912, 3; 1913, 0. 



88 Russell. Am. Journ. of Med. Sc., Vol. 146, Dec., 1913. 



