﻿NO. 8 RECOVERY FROM INFECTION FLEXNER 9 



of the condition in spontaneous recovery or the reverse depends 

 upon the degree of this response and the competency of the curative 

 bodies evoked to reach and to suppress the infectious agents. 



The normal body possesses, therefore, great potential power of re- 

 sisting infection, and this power can be quickly raised, on demand, 

 to a higher level, so as to ward off disease through a rapid augmen- 

 tation in the number of circulating white corpuscles or phagocytes, 

 and by means of an increase in the dissolved principles, the purpose 

 of which is to act upon and injure the parasites and to neutralize 

 their toxic or poisonous products. This process is either identical 

 with or closely related to that which takes place during recovery 

 from infection, which consists in the bringing into being of a new set 

 of operations that gradually reinforce the natural resistance — a pro- 

 cess termed immunization. The indications of the immune condition 

 are found in the appearance in the blood sometime between the fourth 

 or fifth and the tenth day of the disease, and somewhat later than they 

 have appeared in the spleen and bone-marrow, of highly potent sub- 

 stances that are directed in a specific manner to the direct neutraliza- 

 tion of the poisons which have been and are still being produced by 

 the parasites, and to the destruction of the parasites themselves 

 through heightened phagocytosis. As recovery progresses, the solu- 

 ble immunity principles continue to increase, until, at the termination 

 of the disease, they are present in the blood in quantities that suffice, 

 often, by a passive transfer to another individual, to protect him 

 more certainly from infection or to terminate abruptly an infection 

 already established. If, in imagination, we substitute for man a large 

 animal, such as the horse, and if we conceive the immunization pro- 

 cess to be carried forward by design and in a manner to cause the 

 minimum of damage and to produce the maximum of immunity 

 response, we have presented to our mind's eye the principles as well 

 as the method upon which the serum treatment of disease is based. 



I should like to emphasize, at this point, the fact that the founda- 

 tion of the modern specific treatment of infectious disease by serums, 

 by inoculation of dead bacteria, and even by specific chemical com- 

 pounds, rests upon the working out in laboratories, upon animals 

 and man, of the manner in which spontaneous recovery from disease 

 takes place. I need not remind you that the leading physicians 

 rarely failed to appreciate the unexcelled power of nature to heal her 

 self-inflicted wounds and to recognize that many diseases tend of 

 themselves to progress toward recovery. It has been through 

 imitation of nature's way of curing disease that the efforts at modern 

 control have been forwarded. 



