THERAPEUTIC IMMUNIZATION IN MAN 511 



by a method suggested by Kraus. Kraus, 152 reasoning from the fact 

 that syphilis like hydrophobia was a disease with Ipng incubation 

 time, expressed the hope that perhaps the method of Pasteur in 

 hydrophobia, that is, active immunization during the period of in- 

 cubation might, in syphilis also, tend to abort the disease. Accord- 

 ingly, Spitzer treated 15 cases of early syphilis immediately after 

 the appearance of the chancre by subcutaneous injections of emul- 

 sions made from human chancre material in dilutions of 1 :200 to 

 1:20. The cases received from 11 to 20 injections and in seven of 

 them the disease was uninfluenced. In the others, however, subse- 

 quent symptoms were delayed, and in four, no generalized symptoms 

 occurred. In a later communication, Spitzer reported 23 further 

 cases similarly treated, 10 of which failed to develop generalized 

 symptoms and in 9 of these the Wassermann test remained negative. 

 One of them, a fact which is of great importance, was spontaneously 

 reinfected with syphilis two and one-half years later. These results, 

 if accurate in every way, are of the greatest importance, but are 

 diametrically opposed to the experience of all other investigators. 

 Monkey experiments along the same lines by Neisser gave entirely 

 negative results and Brandweiner 153 as well as Kreibich 154 were 

 unable to confirm Spitzer's results in man. Further comment on 

 the Kraus and Spitzer method is valueless without more experi- 

 mental data. It is one of the few rays of hope, but so isolated that 

 one is forced to skepticism. Metchnikoff and Roux did almost the 

 identical thing in an orang-outang and obtained lesions both at the 

 point of the original inoculation as well as that at which the subse- 

 quent "protective" injection was made. 



The only experiments in which an attempt at vaccination with 

 attenuated virus was made with some indication of efficacy, is one of 

 Metchnikoff and Roux, the outcome of an accidental laboratory in- 

 fection. It appears that a laboratory assistant who had been attend- 

 ing to the animals, noticed a small lesion on his lip which did not 

 look like a typical syphilitic chancre. In order to allay the patient's 

 fears, however, Metchnikoff and Roux did inoculations from the 

 patient to monkeys and these were positive. Nevertheless, Fournier 

 after examining the original lesion declared it so unlike the ordinary 

 primary sore that he did not advise treatment. No secondaries de- 

 veloped in the patient nor in the three chimpanzees inoculated with 

 the material. From this occurrence Metchnikoff and Roux con- 

 cluded that the patient had probably been infected in handling the 

 monkeys, and that the virus had become attenuated by passage 

 through these animals. On the basis of this observation they later 

 inoculated a willing subject 79 years old with virus carried for five 



152 Kraus. Wien. klin. Wchnschr., 1905, No. 41, and 1906, No. 21. 



153 Brandweiner. Wien. med. Wchnschr., 1905, No. 45. 



154 Kreibich. Wien. klin. Wchnschr., 1906, No. 8. 



