74 ANAPHYLAXIS AND ANTI-ANAPHYLAXIS 



What is the mechanism of this anti-anaphylactic 

 vaccination ? 



The following passage was written on this subject 

 in 1907, in one of our first memoirs dealing with 

 anaphylaxis:^ "Anti-anaphylactic vaccination, which 

 may be effected either intraperitoneally or intra- 

 cerebrally, is very probably a phenomenon closely 

 allied to that of neutralisation of tetanus toxin in 

 vitro with antitetanic serum. Vaccination should 

 amount, therefore, to a desensitisation, and should 

 have the effect of restoring the guinea-pig to its 

 original state; anti-anaphylactic immunity should 

 therefore be nothing else than that natural immunity 

 which every normal guinea-pig possesses in the 

 presence of intracerebral injection of serum." 



We have nothing further to add to this at the 

 present date. Indeed, from the time when we dis- 

 covered that the sensitised guinea-pig became forth- 

 with vaccinated by a single injection (and that in an 

 exceedingly short space of time) we grasped the fact 

 that anti-anaphylactic immunity had nothing in 

 common with other recognised processes of immunity 

 — that is to say, with those against bacteria and their 

 toxins. In fact, ordinary antitoxic or antibacterial 

 immunity is not established till after the lapse of eight 

 days at the least. It becomes more effective as the 

 number of injections is increased, and the immuni- 

 sation is of longer duration. It is accompanied by 

 the appearance of antibody in the serum. It never 

 protects against the inoculation of virus into the 

 nerve-centres . 



On the other hand, anti-anaphylactic immunity is 

 estabUshed after a single injection. It is, so to speak, 

 instantaneous. It is not accompanied by the appear- 

 ance of antibody, but, quite on the contrary, by the 

 disappearance of antibody or of the sensibiHsin. It 

 1 Annates de VInstitut Pasteur, April, 1907* 



