IMMUNITY IN PNEUMOCOCCAL INFECTIONS 5 



For this purpose, he employed pneumococci of the highest virulence 



such that one-twenty-millionth part of a cubic centimetre of a culture 

 killed rabbits of any weight in six days. The asses' serum gave the best 

 results, for an injection of 075 cc. into the auricular vein of a rabbit 

 protected it against twenty times the minimal lethal dose, even when this 

 was injected thirty to sixty minutes before infection ; while, from the 

 serum of a rabbit, i cc. was required to attain the same result. Quantities 

 of 3 cc. of the asses' serum protected against 20,000 times the minimal 

 lethal dose of pneumococcus culture. 



Pane then applied himself to the treatment of pneumonia in man with 

 his highly active anti-serum, but the results did not justify his expecta- 

 tions. He treated 32 cases, with three fatal issues, and is convinced that, 

 in cases which are not severe, a fatal issue may be averted by doses of 

 20 cc. given early and frequently. The behaviour of Pane's serum with 

 different races of pneumococcus was tested by Eyre and Washbourn (S), 

 and they found that it was active for four strains out of five, and was a 

 valuable means of separating different strains. 



The serum most widely used at the present day is that of Romer (9). 

 What he attempts to do is to produce a highly bactericidal anti- 

 pneumococcic serum, starting with the assumption that the antibodies 

 produced in the serum were of the nature of amboceptors. The specificity 

 of the immune bodies may be so great that in infection by one strain of a 

 particular bacterium, the amboceptors formed are not capable of attaching 

 themselves to the bodies of the bacteria of another strain, and, therefore, 

 to have a universally active anti-serum, amboceptors suitable to all 

 variations of the bacterial species pathogenic to man must be inoculated. 

 Since the labile complement cannot be preserved, we can have only 

 the amboceptors to deal with in a bactericidal immune serum. 

 There are great difficulties connected with the production of fresh 

 complements, because the inoculation of fresh serum may give rise 

 to the production of anti-complements in the organism (Ehrlich and 

 Morgenroth). To overcome these difficulties, Romer employs the 

 mixture of immune sera from various animals (horse, bovines and sheep) ; 

 each of these animals has been immunised against different strains of 

 pneumococcus (according to the principle Tavel employs in the production 

 of antistreptococcic serum) and mixes them. Thus Romer's serum 

 is polyvalent in a double sense, in that it contains different immune 



(369) Z 



