82 VACCINE AND SEEUM THERAPY 



2. Use of attenuated cultures. 



3. Use of cultures and immune serum. 

 Vaccination by any of the above methods establishes 



active immunity. 



Passive immunity is given by the use of immune 

 serum, and this method is indicated to immunise the 

 in-contact animals in an actual outbreak. 



x\ll the organisms belonging to the bipolar group 

 have a close relation, inasmuch as the serum prepared 

 from one species is not strictly specific for that species, 

 but has immunising properties for all the varieties. 

 However, the immunising properties of the serum are 

 most marked for the variety of organism from which 

 the serum is prepared. In the early stages of the 

 disease, if serum is given in doses of 50 to 100 cc. 

 or more, good results will follow. The serum should 

 be given intravenously. The serum now in use is 

 generally polyvalent — that is, several virulent varieties 

 of the bipolar bacilli are employed in hyperimmunis- 

 ing the animal which produces the serum. A similar 

 polyvalent vaccine has been prepared by Lignieres, 

 and has met with much success in practice, especially 

 in establishing immunity against the acute forms of 

 infection. Statistics show that the most favourable 

 results have been obtained from vaccination by the 

 serum simultaneous method. The vaccine employed 

 is generally polyvalent. 



Dose : 2 cc. of vaccine and 20 to 40 cc. of the 

 immune serum. 



In actual outbreaks the serum may be given in 



