IX. CONCERNING THE MODE OF ACTION OF BACTERI- 

 CIDAL SERA. 1 



By MAX NEISSER, Member of the Institute, and Dr. FREDERICK WECHSBERG. 



OUR experiences with diphtheria curative serum have taught us 

 that in antitoxin the employment of a high dose of antitoxin is of 

 primary importance. It is immaterial whether an excess of antitoxin 

 is administered, since it may be regarded as certain that an excess 

 does no harm and can on the contrary only be of benefit. 



Concerning the action of bactericidal sera, however, the litera- 

 ture contains a number of examples which indicate that here an excess 

 of immune serum is occasionally injurious. Thus several high 

 authorities have published protocols of therapeutic experiments on 

 animals which seem to contain paradoxical results ; for with the same 

 infection and varying amounts of immune serum not only those 

 animals died which had received the smallest amounts of serum but 

 also those which had received the largest amounts. Only those 

 animals were protected which received doses of immune serum lying 

 between these extremes. Such a protocol, for example, was published 

 by Loffler and Abel 2 on their experiments with bacillus coli and a 

 corresponding immune serum. Out of nineteen guinea-pigs which 

 had been inoculated with the same amount of culture (Vio loop) 

 and had received varying amounts of the immune serum, only six 

 animals were protected, those which had received doses of 0.25 to 

 0.02 cc. Eight animals with larger doses as well as five with smaller 

 doses of serum died. 



A similar protocol is that of R. Pfeiffer, 3 which states that of four 

 guinea-pigs treated with virulent cholera and a corresponding im- 

 mune serum only the two animals receiving the medium doses 

 survived. 



1 Reprinted from the Munch, med. Wochenschr. , 1901, No. 18. 



2 F. Loffler and R. Abel, Centralbl. f. Bact., 1896, Vol. 19, page 51. 

 1 R. Pfeiffer, Zeitschr. f. Hygiene, 1895, Vol. 20, page 215. 



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