922 



ANTIBACTERIAL SERA 



influence over any heterologous type, nor are monovalent anti-meningococcus sera of 

 value in treatment of an infection due to strains other than that used in producing the 

 serum. 



By way of contrast, we have, in the case of the diphtheria bacillus, at least five 

 immunological types distinguished by the action of the antibacterial immune bodies. 

 All of these produce toxins which are identical in effect. The antitoxin produced in 

 response to the injection of any of these toxins will neutralize all such toxins, regard- 

 less of the immunological type of the diphtheria bacillus from which they are derived. 

 This is also true of the tetanus bacillus. Such findings indicate that, since the toxins 

 are identical, they have a common origin, and are in accord with the idea that they 

 are a degradation product of some component of the medium in which they grow, 

 and not a direct product of the organisms themselves. 



On the other hand, bacterial antibodies are produced in direct response to stimu- 

 lation by the bacterial bodies themselves, or their components, and so tend to be 

 highly specific. In a disease process the antigens or bacteria present are highly 

 specific. Since both the serum and the antigens are so specific, a useful serum must 



TABLE I 

 Mortality Percentage Compared with Day of Beginning Therapy 



contain antibodies specific for the organisms likely to be encountered, i.e., it must be 

 polyvalent enough to have a wide range. This requisite renders the proper immuniza- 

 tion of serum-producing animals a difficult matter. 



The best established of the antibacterial sera is anti-meningococcus serum for the 

 treatment of epidemic cerebrospinal meningitis. This serum has had wide usage and 

 is generally accepted as being specific for this disease. But even here, with an organ- 

 ism as homogeneous and true to type as the meningococcus, there exist several well 

 defined immunological subgroups, and it is necessary to include all of them in the 

 immunizing doses in order to produce a generally useful serum. Occasionally, aberrant 

 strains are found which do not fall in the established groups, and as these appear their 

 use is required for immunization. So, at the time of writing, from twelve to fifteen 

 different strains are employed for immunization. 



When we attempt to analyze the effects of antibacterial sera we find little infor- 

 mation as to the ultimate mode of action of the antibacterial immune bodies as cura- 

 tive agents within the body. We do know that, when specific serum is injected in 

 pneumococcus infections, the organisms present in the bloodstream promptly aggluti- 

 nate. We know that they presently disappear from the bloodstream and in the pres- 

 ence of sufficient antibody do not reappear. It has also occurred that, in cases of pneu- 

 mococcus meningitis, the administration intraspinally of pneumococcus antibody 



