Immunization. 251. 



there have resulted in more effective methods by which more 

 satisfactory results are being obtained in affected localities. 



I. Immunization with Secretions of Affected Animals. 



Stimulated by the favorable results of smallpox vaccination, 

 immunization against rinderpest was undertaken in the niiddie 

 of the eighteenth century (1744) in England (Dodson), in 

 France and in Germany, as well as in Holland, and later was 

 employed to a great extent in Russia. 



The procedure consisted in the introduction of the nasal discharges or lachrymal 

 secretions of affected cattle into healthy animals, under the skin of the tail or 

 other parts of the body. After the inoculation the disease developed in a very mild 

 form, especially in the gray range cattle, and the mortality reached only a small 

 percentage. Jessen experimented later with a supposedly attenuated virus, which 

 he carried through several generations of cattle. After such inoculations in the 

 Vaccine Institute of Karlowka, in the years 1857-1873, the entire loss among 

 2629 cattle amounted to only 5.97%. 



This method of immunization, however, did not appeal to Western Europe, 

 inasmuch as the breeds of cattle in those countries became severely affected from 

 the inoculation and the losses were considerable, and further than this, the inoculated 

 animals endangered the lives of those which had not been treated. After the inter- 

 national conference in Vienna in 1872 had resolved that the immunization against 

 rinderpest should not be considered as a valuable method, it was abandoned even 

 in Russia, and in 1874 the last serum institute was given up. 



II. Immunization with the Bile of Affected Animals. The 



blood and the bile of animals dead from rinderpest has been 

 used for a long time for immunization purposes by the Boers 

 in the Transvaal and in the Orange Free States. Koch later 

 demonstrated (1897) that the bile of such animals in quantities 

 of 100 cc. injected into healthy animals afforded them a very 

 valuable immunity against the infection. The immunity can 

 be established by the tenth day following the immunization, 

 and is of such intensity that the immunized animals withstand 

 an injection of 40 cc. of virulent blood without ill effects even 

 four weeks after the inoculation, and they are also able to 

 resist natural infection. The immunity probably results from 

 the virus contained in the bile which gives the animals a mild 

 local affection, due to the retention of the virus at the point 

 of inoculation through the action of certain ingredients of the 

 bile (Kolle). 



The immunization employed in practice showed that the immunity 

 following the injection of bile sometimes appears on the sixth day, 

 and lasts from four to six months (Kolle). In other cases, however, 

 it lasts only from 3-4 weeks (Kohlstock), and the inoculation occa- 

 sionally causes not only a local swelling at the place of inoculation, 

 but it may also cause a severe general affection, and exceptionally 

 the death of the animal, especially if the bile contained some blood 

 (Theiler). Further, as the bile inoculation in already infected animals 

 during the time of incubation is entirely without effect, the applica- 

 tion of this method could only come into consideration if rinderpest 

 suddenly broke out in certain localities and a more effective method 

 of immunization could not be employed. 



Potent bile can be obtained only after the seventh day of the dis- 



