CLINICAL SIGNIFICANCE OF ANAPHYLAXIS 435 



sensitization the toxic dose of 1/2 slant being given fifteen days 

 after the last of these. 



In order to obtain some opinion regarding the possible dangers 

 of vaccine therapy in this regard the writer a few years ago ob- 

 served carefully a pair of young goats, animals extremely favorable 

 for anaphylactic experiment (and of approximately the weight of a 

 child of three) in the course of frequent and irregularly spaced 

 intravenous injections of typhoid bacilli. In both cases marked 

 anaphylactic symptoms were observed after the animals had attained 

 a considerable agglutinative and bactericidal power (1 to 5,000 to 

 1 to 20,000), but in each case only after intravenous injections of 

 large quantities of bacteria, 1/2 to 2 slant cultures. While, of 

 course, such experiments are not conclusive in any way, from these, 

 as well as from a number of laboratory accidents in the course of 

 animal immunization, it is the writer's impression that the intrave- 

 nous injection of bacteria or bacterial products in human beings 

 would be a procedure involving some risk, unless more thorough, ex- 

 perimental data than we at present possess were available to guide 

 us as to dosage and intervals. The ordinary subcutaneous treatment 

 of patients, however, with bacteria in the amounts customarily em- 

 ployed in vaccines would seem to be practically without risk as far 

 as acute anaphylaxis is concerned. 



In the treatment of animals with vaccines of various kinds Le- 

 clainche 2021 has repeatedly called attention to the fact that inocu- 

 lation with a vaccine may lead to a condition of hypersusceptibility, 

 serving to light up a latent lesion which might have been held in 

 check if the normal resistance had not been interfered with. This 

 objection, we have seen, has been made on numerous occasions against 

 tuberculin therapy, and is one of the factors which have led to the 

 great caution in dosage and control of all therapy based on active 

 immunization. These considerations, even more than the rather 

 remote dangers of serious active anaphylaxis, require that all forms 

 of specific therapy should be carried out only under the safeguards 

 of thorough familiarity with the experimental phases of such work. 



Our own recent studies on anaphylatoxins, moreover, have in- 

 clined us to believe that hypersusceptibility to bacterial protein may 

 well be a strong predisposing factor in infection. 



Serum sickness, occurring as a direct consequence of the injection 

 of a foreign protein into a human being, forces itself upon us as 

 manifestly related to anaphylaxis. There are a number of other 

 clinical conditions which are less obviously anaphylactic in nature, 

 but in which we have many good reasons for attributing an important 

 part of the etiology to a state of hypersusceptibility. Thus the pe- 



20 Leclainche and Vallee. Ann. de I'Inst. Past., 1902. 

 21 Leclainche. Revue Gen. Med. Vet., Sept., 1911; Bull, de I'Inst. Past., 

 9, 1911, p. 1089. 



