286 IMMUNOLOGY 



mime serum by methods of concentration, but it was not until 

 1924 that a satisfactory method was devised. This was accom- 

 plished by Felton whose concentrated antibody solutions of Types 

 I and II sera are now used extensively. Efforts to produce an 

 effective Type III antibody solution have been uniformly unsuc- 

 cessful. Up to the present time the best results obtained in the 

 serum or concentrated antibody treatment of pneumonia are in 

 Type I and to a lesser extent in Type II infections. The introduc- 

 tion of a type specific antipneumococcic rabbit serum promises bet- 

 ter results in some types other than I. (Goodner, Horsfall and 

 Dubos, 1937.) 



Result of Serum Treatment. — To be effective large intra- 

 venous or intramuscular injections should be administered early 

 in the disease ; i.e., before the fourth day. Statistics indicate that 

 the mortality can he reduced 50 per cent by such treatment. The 

 serum treatment of pneumonia has been most successful with 

 severe cases Avhen combined with chemotherapy. An excellent dis- 

 cussion of serum therapy and chemotherapy in pneumonia is 

 given by Finland, Spring and Lowell (1940). Bullowa (1934) 

 reports definite therapeutic value for Type VIII serum in pneu- 

 monias due to the corresponding type of pneumococcus. This 

 is interesting in vicAV of the close relationship of Type VIII and 

 Type III pneumococci and the ineffectiveness of serum therajiy 

 in pneumonia due to the latter. 



Enzyme Treatment of Type III Pneumococcus Infection. — 

 While serum therapy has been found ineffective in the treatment 

 of Type III pneumococcus pneumonia Dubos and Avery (1931) 

 report that a bacterial enzyme, which they had previousl^y re- 

 ported (1930) as possessing the property of destroying the capsu- 

 lar polysaccharide of the Type III pneumococcus, is of thera- 

 peutic value in the treatment of Type III pneumococcus infection 

 in mice. Goodner, Dubos and Avery (1932) report that dermal 

 infections (Type III pneumococcus) in rabbits undergo an early 

 termination with recovery following the intravenous injection of 

 adequate amounts of the enzyme. The infection is fatal in un- 

 treated animals. Whether this method can be used to treat suc- 

 cessfully Type III pneumococcus infection in man remains to be 

 determined. It has long been known that the capsule is associ- 

 ated with virulence, and as a result of the extensive work of 



