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APPLIED IMMUNOLOGY 



developed typhoid fever with no fatahties. Anti- 

 bodies reach their height usually within two weeks 

 after the first inoculation and immunity is alleged to 

 be absolute for one or two years and may endure for 

 many more, although it is advisable to reinoculate 

 after one year if an epidemic threaten or the individual 

 be exposed. The most approved doses for protective 

 inoculation and those adopted by the United States 



Fig. 57. — Illustrating typhoid-fever rates in United States Army. Shaded columns rep- 

 resent decrease in incidence of typhoid; black areas, the decrease in death-rate. 



Army are: First dose 500,000,000; second and third 

 doses 1,000,000,000 each. Intervals of a week to ten 

 days must separate the inoculations. In over 500,000 

 inoculations in the Army and Navy no bad results 

 have been reported. Clinically, the majority of those 

 inoculated develop fever rarely over 101° F., but at 

 times exceeding even 103° F. Headache, malaise 

 and muscular aches are commonly observed; rarely 

 chills, nausea and vomiting occur. Agglutinins and 



