54 MODERN BIOLOGIC THERAPEUSIS 



tion. Hence, the more acute the infection, the 

 greater is the indication for introducing an im- 

 mune serum. In chronic infections and in some 

 acute infections, we may practise active immuni- 

 zation by introducing a vaccine with the pur- 

 pose of stimulating dormant cells to produce 

 antibodies; but as a rule it is reasonable to as- 

 sume that in a severe generalized infection, the 

 tissue-cells are doing their utmost to overcome 

 the infection and an extra stimulation may be 

 actually harmful. By introducing antibodies 

 produced in some other animal, however, prac- 

 tically no extra strain is thrown upon the cells. 

 On the contrary, the tissue-cells may be relieved 

 when the new antibodies overcome the infec- 

 tion, and in this manner an opportunity is af- 

 forded the cells to build up the bodily vitality. 



