222 A MANUAL OF BACTERIOLOGY 



This method has also been proposed for plague, and vaccinia must 

 be regarded as being of this nature (this is the " Pasteurian 

 method "). 



(2) Killed cultures, autolysed cultures, and endo-toxins. The 

 first and second are used for typhoid, plague and dysentery, and 

 Hewlett has suggested endo-toxins for typhoid, cholera, plague and 

 diphtheria. 



(3) Immune sera give protection for a limited time. 



(4) Besredka has suggested " sensitised vaccines," i.e. living 

 cultures saturated with the homologous immune body derived from 

 an immune serum. He claims that the organisms being unaltered 

 by heating, etc., the vaccine gives better results than a dead vaccine, 

 while the saturation with the immune serum prevents infection 

 although the organisms are living. 



(For further particulars, see Hewlett's Serum Therapy, ed. 2, 

 J. and A. Churchill, 1910.) 



