Vaccination. Immunization. 317 



Peuch diluted for this purpose the lymph obtained from the vesicles with 60-100-160 

 times its quantity of water, Nocard & MoUereau with water containing oxygen, 

 Semmer & Eaupach by heating to 55°. After the inoculation of such vaccines no 

 eruptions resulted, nevertheless the respective sheep proved immune. Duclert kept 

 fluid lymph, Conte dried lymph, at a temperature of 25°, and both observed a 

 gradual attenuation of the virus. The vaccinations undertaken with such attenuated 

 virus, however in numerous cases failed to give positive results. 



Supposing that the ovina becomes attenuated in virulence for sheep by passage 

 through goats Konew employs for the vaccination of sheep, edema fluid obtained 

 from goats (Kaprino) which have received serial subcutaneous vaccination with 

 ovina. Up to 1907, 91,735 sheep were vaccinated with such lymph in Russia with 

 uniformly satisfactory results, and Bridre also obtained the same good results 

 in an outbreak. Voigt also convinced himself that sheep caprinized with goat ovina 

 became immune, only he found that a necrosis of the point of vaccination developed 

 from the subcutaneous, as well as from the cutaneous injections. 



Following the initiative of Sacco, sheep were vaccinated for a time with 

 cow pox lymph, but without results. At the same time it was learned that vaccina- 

 tion with cow pox lymph took only in few sheep (Pessina), and it was observed 

 that after such vaccinations a generalized pox eruption with considerable loss 

 occurred (Fiirstenberg, Gips). 



Serum Immunization and Serum Therapy. Duelert (1896) found 

 that blood serum of sheep which have passed through an attack of 

 pox, and more so from those which were repeatedly treated with virulent 

 lymph, has a protective action for lambs against an energetic infection 

 of virulent lymph. Borrell (1902) inaugurated this procedure in 

 practice. 



Sheep which have recovered from pox are injected suboutaneously every month 

 with 200-300 cc. of lymph prepared by his method (see p. 316). After 5-6 of 

 such injections the sheep produce a potent blood serum. If such serum is mixed 

 with lymph obtained from pox vesicles, and diluted with 53 parts of bouillon, a 

 cutaneous inoculation with such a mixture produces results according to the quantity 

 of the serum, smaller and smaller vesicles are developed as the amount of serum 

 is increased while a mixture of 1 cc. of diluted lymph with % cc. of blood serum 

 proved entirely ineffective. The cutaneous inoculation of 1 cc. of diluted lymph 

 produces a blister with a diameter of 6-7 cm., and subsequently a general pox 

 eruption. If on the other hand such sheep receive two days after the inoculation, 

 from 2-10 cc. of blood serum, the size of (the vesicles is diminished in accordance 

 with the serum used, and if 15-20 cc. of blood serum is injected, no eruption 

 whatever develops. 



Immune serum has been used in practice in France with good 

 results, it is claimed, although mostly under very unfavorable condi- 

 tions. According to Martel's view the serum inoculation checks the 

 disease in infected herds, and also prevents the eruption of pox in 

 already febrile (40 degrees) sheep. If the eruptions are already in 

 progress usually only a few small vesicles develop, and even if they do 

 become larger, recovery takes place within a short time. In some sheep 

 only small nodules which do not suppurate, develop under the skin. The 

 serum immunization is supposed to confer also an immunity on the 

 otherwise very susceptible lambs, which lasts for at least 40 days 

 (Borrel). 



The dose of the blood serum is for the immunization proper 5 cc, for 

 therapeutical purposes at least 10 cc. In already infected animals the serum 

 affords only a protective or curative action in the incubative stage or, at best, 

 in the prodromal stage of the disease. 



The value of serum imniunization cannot yet be definitely established. In 

 the fall of 1902, and in the spring of 1903, six herds were given the serum 

 treatment, in which previous to the treatment 10.3% of the animals died from 

 pox. Of 581 sheep and 352 lambs which were treated, 49 sheep and 24 lambs, that 

 is in all 7.8% died, the loss fluctuating in the individual herds between 0.0 and 

 27.7%. In a herd , consisting of 500 sheep and 150 lambs, in which pox had 

 developed two weeks' previously, the disease ceased immediately after the animals 

 had been injected subcutaneously with 5 cc. of serum. Conte treated 689 sheep 



