VACCINATING INJECTION 67 



ous, intrathecal, or intravenous, we are always certain 

 of being able to protect the animal against spinal 

 anaphylaxis. The only difference that is observed 

 in the selection of the various routes is the rapidity 

 with which anaphylactic immunity is established. 



From this point of view, the subcutaneous route is 

 the least favourable of all — that is to say, anti- 

 anaphylaxis takes the longest time to establish. 

 Thus, the guinea-pig, vaccinated subcutaneously, only 

 acquires immunity against intraspinal injection after 

 some five hours. Intraspinal vaccination is mani- 

 festly more rapid, and we have recourse to it in man 

 whenever practicable. Experiments on guinea-pigs 

 shew that intraspinal vaccination confers anti- 

 anaphylaxis at the end of an hour, or of two hours 

 at the maximum. Immunity is established, then, in 

 this case, at least twice as quickly as by the sub- 

 cutaneous route. 



The most rapid vaccination route is the intravenous. 

 It is not only the most rapid, it is also the surest, as 

 numerous experiments have shewn us ; an animal 

 intravenously vaccinated is already in a state of anti- 

 anaphylactic immunity at the end of ten to fifteen 

 minutes. 



What should be the attitude of the physician at the 

 bedside from the point of view of the anti-anaphy- 

 lactic measures ? Let us point out that while it 

 may be a good thing to be informed of the past serum 

 history of the patient, it is not entirely indispensable. 

 First, the patient is not always able to give informa- 

 tion as to whether he has been previously injected 

 with serum or not; then, there are some subjects 

 who, without having had a serum injection, yet react 

 to the first injection in a violent manner, for reasons 

 which have hitherto eluded us. We advise, there- 

 fore, that the sensibility of the patient should be 

 tested in every case, and that a weak dose of serum 



