'75 Swine Eiysii>elas 



only 4 out of 59,62;j hogs vaccinated in the years 1904-1905 died of acute erysipelas; 

 of the original number, however, 29,249 animals received the usual two injections 

 (Beisswanger), while in the Province of 8axony in the year 1904-1905 of 175,150 

 animals, 12 died of vaccination erysipelas, 6 of endocarditis, and 15 succumbed to 

 erysipelas later (Kaebiger). in Holland in the years 1899 to 1905 out of 165,884 

 inoculated hogs i;u; (0.08%) died as a result of the vact-inations. Keports from 

 Baden (Fehseiuneier), Moravia (Rudovsky), Cantoniurich (Zschokke) and others 

 are much in favor of the value of the simultaneous injections, and the Leclainche 

 method is also used extensively in Hungary with favorable results. 



Preparation of the immune serum". For this purpo^^e healthy horses are 

 used which receive weekly injections, into the jugular vein of virulent bouillon 

 cultures of erysipelas bacilli in increasing quantities (50 to 500 ec). The animals 

 react to the injection with fever, nuiscular trendding and sometimes with diarrhea. 

 After 2 to 3 months of such treatment they produce a blood serum which strongly 

 agglutinates the erysipelas bacilli of which 0.5 cc. protects a pigeon against a like 

 quantity of virulent culture which ordinarily would kill it in SVa to 3 days 

 (Leclainche) ; exceptionally 0.1 of such serum has such a protective action 

 (Deutsch) ; it retains this action for months after heating for % hour to 55° C.^ In 

 Germany oidy serum can be marketed, 0.015 cc. of which will protect a mouse of 15- 

 grams weight against a simultaneous subcutaneous (Lorenz), or against an intra- 

 lieritoneal (Marx) injection of 0.1 cc. of virulent bouillon culture 24 hours later. 



The immune serum used for the inoculation of hogs must possess the strength 

 mentioned and should not be more than one year old, but the virulent bouillon 

 cultures should be fresh and not over a week ol<1. In Germany the imnuine serum is 

 prepared in various laboratories under different nances (Prenzlauer & Lands- 

 berger's serum, Sus^erin), and is placed on the market with the necessary direc- 

 tions for its use. 



Technique of vaccination. Leclainche 's method: In a carefully sterilized 

 syringe of lu cc. ca})acity, 1 cc. of the bouillon culture is drawn up and then 

 the syringe is filled up with the immune serum. After the contents are well mixed 

 hogs of not over 50 kg. weight are injected subcutaneously with 5 cc. on the inner 

 surface of the thigh. If the hogs are heavier, 1 cc. of additional blood serum is 

 given for each in kg. above 50 kg., or in general each heavy hog is injected sub- 

 cutaneously with 9.5 cc. of serum and 0.5 cc. of culture. The second injection 

 follows 10 to 12 days after the first, when the syringe is filled with bouillon 

 culture, and of this each animal receives 0.5 cc. without consideration of the animal 's 

 weight. The injection is also made on the inner surface of the thigh. 



Method of Tjoren?. In this method the immune serum is first injected 

 under the skin of an ear and immediately afterward^ 0.25 to 1 ee. of culture is in- 

 jected into the other ear; 12 to 15 days later the hog is injected with double 

 the quantity of the culture used in the first dof-e. The second injection is also 

 made under the skin of an ear. Relative to the results of the inoculation, it is 

 immaterial whether the bloo<l serum and virus are injected in a mixture (Leclainche) 

 or simultaneously, but in different parts (Lorenz, Schiitz), or if the virus is in- 

 jected several days following the serum (Lorenz). 



A sufiicient protection is only assured after both inoculations, as the first 

 sinudtaneous inoculation produces only a passing rise in the resistance as ])roven 

 experimentally by I'rettner, inasmuch as the bacteria are influenced by the injected 

 serum to such an extent that a sufticient quantity of immune bodies is not \)io 

 duced. 



III. Passive immunization. The imnnme serum may also 

 he used by itself for the immunization of already infected herds 

 (5 to 10 cc). The serum very rapidly produces a passive im- 

 munity which prevents the development of the disease in ani- 

 mals threatened by the infection or when the infection is in 

 the stage of incul)ation (see also page 72), The immunity 

 produced in such a way lasts, however, only a short time. 

 (According to Leclainche, 17 days.) Therefore, these animals 

 should be given the combined or Pasteur's inoculation after 

 their recovery or from 8 to 10 days after the serum treatment 

 in order to produce a lasting immunity. 



