PREPARATION OF VACCINES 67 



The task of preparing vaccines and ascertaining the daily opsonic 

 index is so delicate and time-consuming that it is out of the question 

 for the practitioner to do the work himself. If he wants to treat 

 cases of chronic bacterial infections by the vaccine or bacterine 

 method, he must first ascertain what particular microorganism 

 does the harm, and then get a vaccine prepared from the identical 

 species and use it by hypodermic injection every sixth or seventh 

 day. It is best to start with a minimum dose and watch its effect 

 upon the animal treated. It should be remembered that general 

 improvement frequently, but not always, is coincident with a rise 

 in the opsonic index. 



FIG. 32 



Showing a microscopic field of the vaccine-dilute blood mixture, prepared in order to 

 standardize the vaccine. (Miller.) 



Archibald, in a paper read before the 1909 Chicago Meeting of 

 the American Veterinary Association, and printed in the Trans- 

 actions of the Association, stated that he had very good success with 

 autogenic vaccines prepared by himself in the treatment of quittors, 

 fistulse, and other infective troubles. 



Opsonins are specific bodies, which means that the injection of a 

 staphylococcus vaccine will raise a low opsonic index for staphylococci 

 but not a low index for tubercle bacilli or any other bacterium. 



