OPSONIC INDEX AND VACCINE THERAPY 351 



or not its use in actively progressive tuberculosis may or may not be 

 hopeful, in which particular cases, and by what methods, it is to be 

 applied, these are problems that we have neither the space to deal 

 with nor the experience to summarize properly. They constitute a 

 special field of clinical research, a survey of which may be obtained 

 in such works as that of Bandelier and Roepke, 33 or the more espe- 

 cial experimental studies of Denys. 34 



THE PRODUCTION AND STANDARDIZATION OF VACCINES 



Vaccines in the sense of Wright consist merely of killed cultures 

 of the bacteria with which the patient is infected. In all cases it is 

 extremely desirable to make such vaccines " autogenous," by which 

 we mean that the organism used is one which has been isolated from 

 the case. The difference between various strains of the same species 

 of bacteria seems to make this imperative whenever it is at all pos- 

 sible. The recent investigations of Is^eufeld and Haendel in de- 

 termining that there are a number of types of pneumococcus which 

 are antigenically distinct illustrates this point. The same principle 

 is made clear by the recent work of Rosenau on the streptococcus- 

 pneumococcus group. Especially important is Rosenau's observa- 

 tion that a pneumococcus which he had been able to transform cul- 

 turally by special methods was found to be altered also in its reaction 

 to agglutinins. 



In the development of prophylactic methods of vaccination 

 against epidemic disease like typhoid, cholera, plague, etc., many 

 different methods of antigen preparation have been developed. In 

 typhoid prophylaxis the bacteria have been used dead, living, and 

 sensitized, and even extracts have been employed. In cholera the 

 early use of living cultures by Ferran has given way, in the hands 

 of Kolle and others, to that of dead bacterial emulsions. In plague 

 and a number of other conditions the impression seems to be general 

 that the bacteria should be used in the living, but attenuated, state. 

 Special methods which have been developed in these cases are dis- 

 cussed in another section. 



In treatment of developed diseases with vaccines the method most 

 commonly used is that which has been introduced by Wright, namely, 

 the use of dead cultures. In his earlier experiments Wright culti- 

 vated the bacteria on agar slants for about 24 hours, then washed off 

 the growth with 10 c. c. of sterile salt solution. It will be well to 

 describe in detail the preparation of such a vaccine. 



The bacteria must be isolated from the patient by the usual 

 method of plate cultivation and colony fishing on suitable media. 



33 Bandelier and Roepke. "Lehrbuch der spez. Diagnostik und Therapie 

 der Tuberkulose," 6th Ed., Kabitzsch, Wiirzburg, 1911. 



34 Denys. "Le Bouillon Filtre," Louvain, 1903. 



