PNEUMOCOCCAL VACCINES 501 



Ordman. 819 Bacteriological studies had shown the presence among 

 the native mine population of eighteen types or groups of pneu- 

 mococci other than the Lister Groups C, B, and E (the classical 

 Types I, II, and III). The vaccine, therefore, was made to include 

 eight groups of pneumococci and, in addition, strains of strepto- 

 cocci, the Pfeiffer bacillus, M. catarrhalis, Staphylococcus aureus, 

 and the Friedlander bacillus. The cultures were suspended in salt 

 solution, sterilized by one hour's heating at 60°, and preserved 

 with phenol. The vaccine was injected subcutaneously in three 

 doses at seven-day intervals. The results up to the date of the re- 

 port were sufficiently encouraging to lead Lister and Ordman to 

 believe that the practice would make possible the employment of 

 tropical natives formerly barred from the mines because of their 

 unusual susceptibility to respiratory infections. 



Early in 1935, Felton 418 made a preliminary announcement to 

 the effect that he had tested various water-soluble fractions of 

 Pneumococcus for their immunizing action on man, but the nature 

 of the preparations was not revealed. A single subcutaneous injec- 

 tion of two milligrams of the preparation was given, and in a 

 group of two hundred persons antibody was found to be present in 

 the serum of all individuals so treated fourteen days after injec- 

 tion. The antibody was still demonstrable in the majority of sub- 

 jects after a lapse of three months and in a few tested after ten 

 months. The amount of antibody found as compared to that origi- 

 nally present in the serum of the subjects varied from a seventeen- 

 fold to a ninety-eight-fold increase. All the preparations employed 

 were high in polysaccharide content, but Felton, at the time, had 

 not decided whether the antigenicity of the immunizing agents was 

 due to the polysaccharide, to the polysaccharide combined with 

 some other substance, or to some other cell constituent or product. 



In a more complete report published in the same year, Felton 

 with Sutliff and Steele 434 presented the details of preparation of a 

 variety of antigens derived from pneumococci of Types I and II. 

 A single subcutaneous injection of the different agents was given 



