THE IMMUNIZING VALUE OF COMMERCIAL 
VACCINES AND BACTERINS AGAINST 
HEMORRHAGIC SEPTICEMIA 
By 
L. VAN ES AND H. M'. MARTIN 
In the course of certain studies having to do with hemor- 
rhagic septicemia, we were particularly struck with the difficulties 
which we encountered in the immunization of susceptible lab- 
oratory animals (rabbits). Aside from a rather transitory and 
very unstable immunity secured by the use of an anti-serum 
prepared by us, there was little or no evidence that injections 
of bacterins or vaccines, as made in our laboratory, were followed 
by any degree of resistance against a trial injection of B. 
bipolaris. 
This difficulty in no small degree excited our curiosity re- 
garding the immunizing value of the considerable number of 
“Hemorrhagic Septicemia bacterins and vaccines” which during 
recent years have become such a prominent article of commerce. 
Most of those preparations appear to be based upon a belief that 
by heating or by other means of killing or attenuation of the B. 
bipolaris a dependable immunizing agent can be produced, al- 
though we are not aware that this has been proven to be the 
case by exact laboratory experiments. In addition we have seen 
no evidence that the immunizing value of the products mentioned 
is being controlled by any standard method by either the manu- 
facturer or the user. Considerations of this kind, however, do 
not appear to have a restrictive influence on the sale of those 
substances and we are certain that the amount of money annually 
expended on them by the raisers of farm animals is quite a con- 
siderable one. 
In the hope of securing some information relative to the 
immunizing value of the agents mentioned, we undertook a series 
of experiments in which the immunity of the bacterin and vaccine 
injected laboratory animals was definitely tested by subsequent 
inoculations with B. bipolaris. 
