CHAPTER V 



Immunization with Bacteriophage Suspensions 

 1. the problem of prophylactic immunization 



The fact that following the administration of bacteriophage suspen- 

 sions by injection an effective and durable mimunity is obtained has 

 been stated in a number of my publications. ^^^-^^^-^^^ As we will see, 

 this conclusion based on my own experiments, has been confirmed 

 by a number of different authors. Other authors, on the contrary, 

 report that their attempts at immunization against experimental 

 infections with bacteriophage suspensions resulted in very definite 

 failures. Among this last group may be mentioned Meissner and 

 Baars,"*^^ Kramer^®^ and Levy,^^"* all of whom selected as a test disease 

 the infection of mice caused by B. typhi murium. I may add that I, 

 also, have failed up to the present time to demonstrate an acquired 

 immunity in experimental plague of the guinea pig, and Flu has in- 

 formed me that he has been equally unsuccessful. 



To what is this lack of success in experimental disease due, when 

 such an efficient immunity is obtained in several natural infectious 

 diseases? Undoubtedly the i-easons are multiple. 



In the first place, it is obviously foolish to assume that one can 

 take any suspension of the bacteriophage whatever and inject any 

 quantity whatever into any kind of an animal and thus obtain an 

 immunity. We will see, for example, that although the question of 

 the size of the dose injected does not appear to be of any great impor- 

 tance in the case of avian typhosis, it is, on the contrary, of the utmost 

 importance in the case of hemorrhagic septicemia in the buffalo. 



In the second place, the question of the experimental animal is 

 another factor of consequence. This is shown very clearly by the 

 fact that, stimulated in some way by an injection of a suspension of 

 the bacteriophage, buffalo and cattle acquire a solid and durable im- 

 munity against hemorrhagic septicemia, while, on the contrary, it 

 has been quite impossible, in spite of many attempts, to obtain the 

 slightest immunity in rabbits. Cattle, animals naturally susceptible, 

 are, therefore, capable of being immunized; the rabbit, an animal 

 which does not contract barbone spontaneously, can not be immunized. 



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