222 BACTERIAL VACCINES 



which is removed after the injection has been given by washing with 

 alcohol. 



Both convenience and experimental work to test the comparative 

 efficacy of inoculation into different tissues point to the subcutaneous 

 tissues as the most suitable site for inoculation. The best method of 

 procedure is to pick up a fold of skin between the finger and thumb, and 

 then to push the needle well down into the middle of the fold, and slowly 

 inject the fluid. 



Since it is known that the power of response of the tissues to the 

 stimulus of a vaccine is somewhat limited, it would seem advisable to 

 choose a new site for each successive inoculation. 



The Effects of Inoculation. The local effects produced at the site 

 of inoculation vary considerably, being influenced by the nature of the 

 individual, the variety and amount of the inoculum, and the sensitive- 

 ness of the patient's tissues to stimulation. In the majority of cases 

 the local reaction is limited to a very slight reddening of the skin around 

 the puncture for an area of about one inch. In some instances, oc- 

 casionally encountered where a large number of typhoid inoculations 

 have been made, the reaction after the first dose is more severe than 

 after subsequent doses, and is accompanied by considerable edema, 

 hyperemia, and pain. 



The focal effects about the lesion are exceedingly important in de- 

 termining the reaction of the patient, and serve as a guide to the 

 adjustment of dosage and intervals. Where, in a case of furuncle, an 

 appropriate dose of staphylococcus vaccine is administered, within a 

 few hours increased hyperemia is seen around the focus, and there is a 

 slight increase in the swelling. When very small doses are given, these 

 focal symptoms may practically be absent, but, as a rule, a slight re- 

 action does no harm, but serves rather to show that the vaccine possesses 

 some degree of potency and may aid in the curative process. 



The constitutional effects may also vary within wide limits. An ade- 

 quate, but not excessive, dose may, within a few hours, produce a feeling 

 of lassitude, headache, slight rise in temperature, and acceleration of the 

 pulse-rate. Severe constitutional reactions are generally due to ex- 

 cessive dosage, but may occur in some persons after doses that were 

 previously well borne. 



Frequency and Dosage of Inoculation. No definite rules can be 

 laid down, each patient being a law unto himself. The opsonic index 

 has been largely abandoned as a guide to the administration of vaccine, 

 the reaction and condition of the patient now governing the dosage. 



