194 ACTIVE IMMUNIZATION 



are characterized by a tendency to chronicity, and in which toxins 

 play little or no role. The credit for having established this possi- 

 bility, and for its popularization, undoubtedly belongs to Wright. 



Wright's concept of the rationale underlying the tedious course 

 of some of these infections is essentially based upon the supposition 

 that the autovaccinations which take place in the body of the 

 infected individual are imperfectly interspaced as regards point of 

 time and improperly adjusted as regards dosage, the consequence 

 being that the formation of certain protective substances, and notably 

 the opsonins, takes place irregularly and insufficiently. He expressed 

 the opinion that by following the opsonic curve indications might . 

 be obtained for the introduction of the corresponding organisms / 

 from without as vaccines, both as regards the size of the dose and \ 

 the frequency of the injections, and that it might thus be possible '; 

 to favorably influence such infections as acne, sycosis, furunculosis, I 

 endocarditis, chronic cystitis, pyelitis, tuberculosis, etc. For a 

 consideration of the details underlying Wright's opsonic studies, I 

 must refer the reader to Wright's own publications, and the chapter 

 on the opsonins in the first part of the present work. Suffice it to 

 state at this place that the opsonic index unfortunately did not fulfil 

 those expectations with which it was at first greeted, and that any 

 attempts at vaccine treatment must still be made upon a more or 

 less empirical basis, and with no more definite or accurate index 

 to dosage and frequency of injection than is afforded by the clinical 

 symptoms. But even so, there can be no doubt that a certain 

 amount of good may be accomplished ; how much it is yet impossible 

 to say. So much depends upon the individual case, coincidence, 

 the personal factor in the observer, etc., that conclusions should 

 only be drawn with great care. As yet we certainly do not know 

 enough of what may or what may not be accomplished to warrant 

 any dogmatic statements. 



Preparation of the Vaccines. A great deal of discussion has arisen 

 regarding the question whether or not it is imperative to use auto- 

 genous vaccines, i. e., vaccines that are derived from the individual 

 organism which is responsible for the particular infection, or whether 

 it is permissible to make use of stock vaccines, which may in turn be 

 polyvalent, i. e., composed of organisms derived from a number of 

 cases of the kind that is under consideration, or from one single 

 case, but not from the individual who is to be treated. As long 



