VACCINATING INJECTION 73 



Then we should wait an hour. In a subject sensitised 

 by previous injections, it is not unusual to observe 

 after this small dose (i to 2 c.c.) some slight symptoms 

 — " abortive anaphylaxis." We should wait for these 

 symptoms to cease completely, and after that we 

 shall be able to inject with impunity into the spinal 

 cavity, then and there, 20 to 40 c.c. of serum. 



Vaccination by the intravenous route is the one 

 we should prefer above all the other methods; it is 

 rapid, certain, and also protects against local ana- 

 phylaxis as well as general. As soon as the anti- 

 anaphylactic immunity is acquired, which requires 

 ten to fifteen minutes, a strong dose of serum can 

 be injected equally well intrathecally, intravenously, 

 or subcutaneously, without the patient running the 

 least danger of anaphylaxis . The intravenous method 

 has, moreover, this advantage, that it permits one 

 to observe, with the needle still in the vein, the 

 sensitiveness of the patient. We begin by testing 

 this sensitiveness by introducing intravenously as 

 weak a dose as is desired — o-i c.c. of serum, for 

 example. (The serum is diluted to ten times its 

 volume with physiological saline solution, and i c.c. 

 of this dilution is injected.) If the patient does not 

 react at the end of three to five minutes, another 

 injection of 0-3 c.c. of serum is given (3 c.c, of the 

 dilution) without withdrawing the cannula. We 

 again wait two minutes, and if nothing happens we 

 inject I c.c. of serum (10 c.c. of dilution). At this 

 moment anti-anaphylactic immunity is acquired ; but 

 for greater security, after a further interval of two 

 minutes, we make a last injection of 2-5 c.c. of serum 

 (25 c.c. of dilution). Whatever may have been the 

 degree of the patient's hypersensitiveness before this 

 vaccination, we can be certain that he will now 

 tolerate, without the least trouble, 20 to 40 c.c. of 

 undiluted serum at any stage of the illness. 



