188 ACTIVE IMMUNIZATIOX 



percentages this means that of the entire body of soldiers LM prr 

 cent, were taken ill with fever, which either was definitely recognized 

 or suspected as being typhoid, with a death rate of 9.2 per cent. 

 All these men were non-vaccinated. Compare with this the fact 

 that among the 12,801 men who were concentrated in 1911 at the 

 maneuver camp at San Antonio, all of whom had been vaccinated 

 either before their arrival or as soon thereafter as possible, there 

 developed but a single very mild case, a private who had not com- 

 pleted his immunization, thus giving a percentage of 0.008! During 

 the same period there were reported in the city of San Antonio forty- 

 nine cases and nineteen deaths. 



On the basis of these findings it would appear that \vith modern 

 sanitary methods, coupled with vaccination in the case of those who 

 are likely to be exposed to infection, typhoid fever should ere long 

 become as rare in our hospitals as are smallpox and cholera at the 

 present time. 



Antityphoid Vaccination for Curative Purposes. Since the introduc- 

 tion of antityphoid vaccination for prophylactic purposes various 

 attempts have been made to influence the course of the malady 

 also by such measures. Some writers indeed express themselves 

 quite favorably on this point, but it will no doubt require a great 

 deal of investigation before we can come to any definite conclusions. 

 It should be remembered that we have no indicator to tell us how 

 much to inject and when to inject, and aside from the actual course 

 of the malady, which varies so greatly in different cases, we have no 

 way of knowing whether we are producing an effect at all, let alone 

 whether this is beneficial or otherwise. Whether or not Wright's 

 opsonic index might yet serve some purpose in the study of such 

 cases the future will have to show. 



CHOLERA 



Prophylactic vaccination against Asiatic cholera was first attempted 

 in 1885 by Perron, during an epidemic occurring in Spain. As 

 infection of the human being with the organism in question can only 

 take place by way of the intestinal canal, Perron injected living 

 organisms subcutaneously, using eight drops of a broth culture for 

 the first, and 0.5 c.c. for the second and third, the inoculations being 



