OPSONIC INDEX AND VACCINE THERAPY 347 



X-rays, Finsen light, heat, and a number of other localized methods 

 of increasing the blood supply. This, too, may be the reason for 

 the benefits derived from wet dressings, in that they keep the tissues 

 macerated, soft, and moist. At any rate, it is a matter of local 

 surgical treatment. At the same time, however, there may be sys- 

 temic causes which prevent the complete healing of such lesions, 

 namely, an insufficient supply of circulating antibodies, opsonic or 

 bactericidal substances. These may be sufficient to hold the lesion 

 in check, but since small quantities of bacteria only are in contact 

 with the blood stream, relatively small amounts of antigen are ab- 

 sorbed and antibody formation is consequently deficient. Here we 

 have an ideal condition for vaccine therapy. By isolation of the 

 organisms from the patient's lesion, for which, in this case, there 

 is time, and the careful immunization of the patient with these 

 organisms, the immunity may be considerably increased and cure 

 effected. 



Closely related to this type of lesion are those conditions in 

 which there are localized infections which heal rapidly but recur in 

 quick succession again and again. Such are the common cases of con- 

 secutive crops of boils ; and not dissimilar are the manifestations of 

 erysipelas where the lesion extends along the edges while it heals in 

 the center. There is in this type, probably, a very close balance 

 between protection and offense ; the defensive reaction is sufficient to 

 overcome the localized lesion, but insufficient to set up a permanent 

 systemic protection. A certain amount of local immunity acquired 

 by the tissues of the affected areas may suffice to throw slight weight 

 into the balance on the side of protection, enough at least to decide 

 the struggle ; and this element of locally acquired tissue resistance is 

 in all probability also the cause for the failure of these lesions to 

 recur immediately in the same area. Here, too, treatment with vac- 

 cines is not illogical and may yield good results if properly carried 

 out. 



In generalized systemic infections we must sharply distinguish 

 between cases of acute sepsis in which the bacteria are actively grow- 

 ing and multiplying in the circulation and cases in which blood cul- 

 tures are positive only because the bacteria are being constantly 

 discharged into the circulation from a focus in the tissues. In the 

 former the defenses of the body are overwhelmed by an extensive 

 flooding with the bacteria, and vaccines, if not harmful, are, at any 

 rate, utterly useless since the antigen is already so extensively dis- 

 tributed throughout the tissues that if the body were capable of 

 responding with sufficient antibody formation this would unques- 

 tionably occur without the small additional amount furnished in the 

 bacterial emulsion. Vaccination in such cases is entirely analogous to 

 an attempt to stimulate a degenerated heart muscle with strychnin 

 the whipping of a tired mare. 



