﻿REPORT ON CHOLERA IN MANILA. 425 



is not given. In the further inoculation of a number of human beings with killed 

 cultures, in some of whom the injection was repeated a second and third time, 

 it was demonstrated that there was a distinct .relationship between the bacteri- 

 cidal immunity obtained and the size of the dose. However, there appeared to 

 be no direct relation between the size of the dose and the agglutinative value of 

 the blood, nor between the agglutinative value and the bactericidal power; neither 

 did the number of vaccinations seem to be directly related to the formation of the 

 agglutinins. 



Meinicke, Jaffe and Flemming 20 have carefully considered the binding power 

 of the cholera vibrio in relation to the production of immunity. Their experi- 

 ments performed upon the relation between binding power and virulence are of 

 great practical importance in regard to the subject of protective inoculation in 

 man. They conclude that binding power and virulence are independent of each 

 other, since in some cases the avirulent cholera organism revealed a greater 

 binding power and in others a lesser than certain more virulent ones. They 

 believe that the apparent quantitative differences in the binding power between 

 different cholera strains can be explained by the qualificative differences in the 

 structure of the receptors of the oiganism. They also conclude, although their 

 experiments in relation to this point are few in number, that the virulence of 

 a cholera culture bears no relation to its immunizing power. They were unable 

 to confirm the work of Friedberger and Moreschi in regard to obtaining sera 

 of as high a value from the intravenous inoculation of 1/100 oese of a cholera 

 culture as from a much larger dose. Even with the intravenous inoculation of 

 1/10 oese they were able to produce sera of moderate value only in about 

 half of the animals inoculated. Differences in the value of the sera were much 

 greater when the small doses were used than when larger ones were employed. 

 They believe that Friedberger and Moreschi's results can be explained by the 

 fact that in immunization with such small doses, the value of the serum obtained 

 depends largely upon individual variations in the animals furnishing the serum. 



Fichera's, 21 experiments in relation to binding power and virulence are mainly 

 confirmatory of those of Meinicke, Jaffe and Flemming. This author found that 

 strains of the cholera organism which had been isolated for long periods of time 

 still possessed the same binding power for cholera amboceptors as freshly isolated 

 cholera cultures. Fichera also investigated the relation between the immunity 

 produced and the size of" the dose. He found, contrary to Friedberger and 

 Moreschi, that rabbits inoculated intravenously with 1/100 of a 24-hour culture 

 killed at 60° C. furnished sera which had an agglutinative value of about 1/10 

 or even less of that furnished by animals inoculated with 1/20 of the culture. 

 The bactericidal value of the sera obtained from the inoculation of 1/100 of a 

 culture was about one-fifth the value of the latter. The results of Friedberger 

 and Moreschi, as the author points out, may be explained on the ground of 

 individual variation in the immunity of the different animals. A human being- 

 was inoculated intravenously with 1/100 oese of a cholera culture killed at 60°. 

 but no practical increase in the immune bodies of the serum Mas demonstrated, 

 therefore the author does not recommend this small dose for active immunization. 

 Fichera recalls that, with those methods of cholera immunization in which 

 specific sera are added to the bacteria before inoculation, the immunizing value 

 of the organism is lost in proportion to the saturation of its receptors with 

 amboceptors before the injection. In case the vibrios were saturated, so to speak, 

 with the serum, the animals were only immunized slightly or not at all. 



20 Ztschr. f. Hyy. u. Infektionskrankh., Leipz. (1906), 52, 416. 

 21 Centrbl. f. Bakteriol. Orig. (1906), 41, 576, 671. 

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