350 INFECTION AND RESISTANCE 



influence the course of such infections in animals that the results 

 of vaccine treatment in them are difficult to judge. 



In acute diseases which run a definite course, typhoid fever, 

 pneumonia, dysentery, cholera, plague, and a number of other con- 

 ditions, vaccine treatment during the course of the disease has not 

 much justification. In typhoid fever, especially, specific antibodies 

 appear in the blood in amounts enormously increased above the 

 normal at periods when the patient is still actively ill in spite of the 

 fact that the blood stream has been freed 'of the micro-organisms. 

 Whatever may be our opinion as to the continuance of the disease 

 after bacteria have been driven out of the blood stream, the use of 

 vaccines can only tend to further increase of antibodies which are 

 already present in amounts far exceeding normal. In pneumonia 

 the micro-organisms seem curiously resistant against the attack of 

 the serum antibodies, and in spite of the presence of large amounts 

 of antigen both in the lungs and, for a time, in the circulation the 

 development of immunity is delayed until just before or near the 

 crisis. Since this, however, is usually only a matter of 7 or 8 days, 

 it is hardly likely that the injection of vaccines during this period 

 could markedly alter the ultimate outcome. In plague we have 

 usually an acute septicemia, and here the considerations that we have 

 outlined above are applicable. 



There are none of the acute infectious diseases of specific course in 

 which vaccine treatment after onset seems advisable on theoretic 

 grounds. 31 



As we have stated before, the opinions expressed above are given 

 with the purpose of stating as clearly as we can the logic of vaccine 32 

 therapy as we see it at present. The next ten years of clinical ex- 

 perience may largely modify these views. One thing is certain, how- 

 ever, and that is that the problem can only be settled if treatment by 

 this method is undertaken with the guidance of an accurate bacteri- 

 ological diagnosis, and with bacteriological control of the individual 

 case, so that, when occasion arises, estimations of antibodies can be 

 made. 



To protest against the random use of commercial stock vaccines 

 without laboratory diagnosis and without control is almost a plati- 

 tude. 



In the case of tuberculosis the problem had been actively investi- 

 gated before Wright, and there seems little question that tuberculin 

 therapy properly and cautiously applied has an established value in 

 the treatment of initial and localized tuberculous disease. Whether 



81 See also Theobald Smith, Jour. A. M. A., Vol. 60, 1913, and R. M. 

 Pearce, Jour. A. M. A. f Vol. 61, 1913. 



32 For discussion of various clinical applications of vaccine treatment 

 see symposium on vaccine treatment, Trans, of Ass'n of Amer. Phys. and 

 Surg., Vol. 8, 1910. 



