252 MODERN BIOLOGIC THERAPEUSIS 



As a general rule, the intervals between the 

 doses in acute infections vary from one to three 

 days. After the acute symptoms have subsided 

 as shown by a drop in the temperature and by 

 other signs of improvement the intervals may 

 vary from two to five days. In subacute and 

 chronic infections, the vaccine should be given 

 every four to seven days; the doses being in- 

 creased according to the clinical symptoms. 



MIXED VACCINES 



Cases are frequently met with in which more 

 than one microorganism seems to be con- 

 cerned in the pathologic process, and for these 

 cases combined or mixed vaccines containing 

 all the bacteria seems desirable. The use of 

 mixed vaccines should, however, be restricted 

 to those cases in which careful studies have been 

 made and the bacteriology of the infection 

 determined. Active immunization has been 

 brought into disrepute by attempts to utilize 

 vaccines as a cure-all in diseases in which there 

 is no evidence that they are of value ; in those of 

 undetermined infectious origin ; and in those in 

 which there is no evident infectious cause. In 

 consideration of the scientific basis of active im- 



