PNEUMOCOCCAL VACCINES 499 



soluble specific substance of Pneumococcus, stated that possibly 

 the polysaccharide might prove to be useful for preventive treat- 

 ment of man. 



Another aspect of the possible effect accomplished by the large- 

 scale prophylactic treatment of man with pneumococcal vaccines 

 was suggested by Lister 818 in 1929, who observed that since the in- 

 fluenza pandemic of 1918 the types of Pneumococcus, previously 

 found by him to be responsible for more than 69 per cent of the 

 cases of lobar pneumonia in the Rand, had practically disap- 

 peared, and he attributed the change in the pneumococcal flora of 

 the native workers to the routine practice of vaccination carried 

 on since 1918. The disappearance of the familiar types of pneu- 

 mococci against which vaccine treatment had been directed and the 

 appearance of miscellaneous types in the cases of lobar pneu- 

 monia then occurring was commented upon by Ordman 1033 in 1931. 

 The morbidity and mortality rates from the disease decreased and 

 there was a modification of the character of the pulmonary infec- 

 tion. Ordman, like Lister, believed that these changes had been 

 brought about by the persistent vaccination of the natives. It then 

 became the custom in the diamond mines to treat the native work- 

 ers entering the mines in summer and autumn with the usual vac- 

 cines and to inject those entering in winter and spring with mixed 

 bacterial vaccines, designated "community autogenous vaccines," 

 containing streptococci and the influenza bacillus. 



In a review of the various attempts to protect the miners in the 

 Rand from pneumonia, Orenstein 1035 in 1931 expressed frank skep- 

 ticism concerning the value of the procedure. He had doubts about 

 the importance of the serological classification of pneumococci, he 

 saw a serious complication presented by the multiplicity of types, 

 and was somewhat pessimistic about the alleged immunizing action 

 of pneumococcal antigens as shown by animal experiments. Never- 

 theless, in the next year, Orenstein 1038 reported on the use of mixed 

 vaccines begun experimentally the year before, and from statistics 

 on 40,000 natives so treated suggested that those receiving the 



