PNEUMOCOCCAL VACCINES 489 



Kolmer and Rule 746 " 7 were also investigating the comparative effi- 

 cacy as immunizing agents of suspensions of killed pneumococci of 

 Types I, II, and III. Vaccines containing cultures devitalized by 

 tricresol were injected subcutaneously at intervals of five days into 

 one series of rabbits and similar injections of organisms treated 

 with hydrochloric acid were given through a stomach tube to ani- 

 mals of another series. Although the two immunizing agents were 

 not strictly comparable, the observations led the authors to con- 

 clude that the antigenic action of the vaccines was more pro- 

 nounced when administered by the subcutaneous than by the oral 

 route. The best results were obtained with a minimum of five daily 

 injections. The work of Ross and that of Kolmer and Rule pre- 

 sent no evidence of the advantage, save possibly that of the ease of 

 administration, of ingestion over injection of pneumococcal vac- 

 cines. 



While intratracheal insufflation, as practiced by Cecil and Stef- 

 fen, 214 " 6 is of interest in demonstrating the possibility of inducing 

 immunity by local stimulation, the method obviously is scarcely 

 applicable in the case of man. 



LOCAL AND SYSTEMIC REACTIONS 



Pneumococcal substance, unless in autolyzed or degraded form, 

 is not conspicuously toxic when introduced parenterally into the 

 tissues of man, and vaccines made from pneumococci or some of 

 their constituents (unlike similar preparations prepared from 

 such bacteria as the dysentery and paratyphoid bacilli, the bacil- 

 lus of Pfeiffer, and Bacillus proteus) can be administered in the 

 customary amounts without risk of incurring undesirable or un- 

 duly severe reactions. Cecil 201 ' 208 spoke of both local and general 

 toxic manifestations following the subcutaneous injection of saline 

 suspensions of pneumococci of the first three types when the dos- 

 age equalled several billion organisms. The subjects exhibited va- 

 riations in reactivity, and the severity of the effect could be les- 

 sened by decreasing the individual dose. Malone 864 reported that 



