250 MODERN BIOLOGIC THERAPEUSIS 



DOSAGE OF BACTERIAL VACCINES 



Wright expressed the opinion that, by follow- 

 ing the opsonic curve, indications might be ob- 

 tained for the introduction of vaccines both as 

 regards the size of the dose and the frequency 

 of the injections. Suffice it to say, however, 

 that the opsonic index unfortunately has not 

 fulfilled those expectations with which it was 

 first greeted; and that any attempts at vaccine 

 treatment must still be made upon a more or 

 less empiric basis, and with no more definite 

 and accurate methods of dosage and frequency 

 of injection than is afforded by clinical symp- 

 toms. But even so, there can be no doubt that 

 a certain amount of good may be accomplished ; 

 how much, it is as yet impossible to say. So 

 much depends upon individual cases, the per- 

 sonal factor of the observer, etc., that conclu- 

 sions can only be drawn with great care. As 

 yet, we do not know enough of what may or may 

 not be accomplished to warrant any dogmatic 

 statement. 



The general rule in vaccine therapy is to be- 

 gin with small doses and progressively in- 

 crease; immunity being more effectively pro- 

 duced by repeated injections of gradually in- 



