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ACTIVE IMMUNIZATION. 



The drawback to this classical method of Pasteur, consists in using the 

 virulent material rather late in the course of the inoculations. A more 

 energetic treatment has therefore been advised. There is no added danger 

 in doing this because the virus fixe in contrast to the street virus is not at all 

 or only slightly infectious for man. 



Hogyes in Buda Pesth uses the virus fixe right from the start. He begins 

 with marked dilutions (1/10,000) and gradually increases them to i/ioo. 

 The theory underlying this procedure is, that the usual method of attenu- 

 ation by drying alters the quantity of the virus but not its quality; hence the 

 same result may be obtained by simple dilution. 



Ferran successfully employs the virulent virus in large doses right from 

 the onset of the treatment. Especially in very severe infections, as in bites 

 from wolves, is this procedure justifiable. 



The exact arrangement of doses varies a little at different institutions. 

 In Berlin, it is considered that the virulence of the dried cord is lost on about 

 the eighth day instead of the fourteenth. Hence in the hydrophobia depart- 

 ment of the Berlin Institute for Infectious Diseases, the authorities have 

 adopted the following scheme, which stands midway between Pasteur's 

 classical method and the extreme procedure of Ferran. 



Scheme for treatment of mild infections : 



