34 Pneumonia 



Immunity. Pneumonia is peculiar in that recovery is 

 followed by immunity of such brief duration as to permit 

 the occurrence of frequent relapses; and it is well known 

 that many cases show a subsequent predisposition to fresh 

 attacks of the disease. 



Immune Serum. G. and F. Klemperer* have shown 

 that the serum of rabbits immunized against the pneumo- 

 coccus protects animals infected with virulent cultures. 

 When applied to human medicine, the serum failed to 

 do good. 



The treatment of pneumonia by the injection of blood- 

 serum from convalescent patients, tried by Hughes and 

 Carter,! has been abandoned as useless and dangerous. 



More recent antipneumococcic serums have been experi- 

 mentally investigated by De Renzi,{ Washbourn, and 

 Pane. 1 1 



Washbourn prepared an antipneumococcus serum that 

 protected rabbits against ten times the fatal dose of live 

 pneumococci, in doses of 0.3 c.c. In general, the lines upon 

 which he operated were those of Behring, Marmorek's work 

 with the streptococcus furnishing most of the details. 

 Two cases of human pneumonia seem to have derived some 

 benefit from large doses of this serum. The serums of Pane 

 and De Renzi were not so powerful as those of Washbourn, 

 requiring about i c.c. to protect a rabbit. 



McFarland and Lincoln** succeeded in immunizing a 

 horse against large doses of a virulent culture of the 

 pneumococcus and obtained a serum, of which 0.5 to 

 0.25 c.c. protected rabbits from many times the fatal dose. 



The antipneumococcic serums thus far produced have 

 given disappointing results in clinical application, probably 

 because their preparation was based upon an antagonism to 

 the toxic products of the pneumococcus rather than upon the 

 destruction of the organism itself. From the most recent 

 investigations upon immunity it is evident that in all dis- 

 eases in which blood invasion is as frequent as in pneumonia, 



* "Berliner klin. Wochenschrift," 1891, Nos. 34 and 35. 

 t "Therapeutic Gazette," Oct. 15, 1892. 

 I "II Policlinico," Oct. 31, 1896, Supplement. 

 "Brit. Med. Jour.," Feb. 27, 1897, p. 510. 



|| "Centralbl. f. Bakt. u. Parasitenk.," May 29, 1897.. xxi, 17 and 

 18, p. 664. 



** "Jour. Amer. Med. Assoc.," Dec. 16, 1899, p. 1534. 



