PRODUCTION OF ANTIPNEUMOCOCCIC SERUM 565 



incidence of chills by at least 50 per cent in patients undergoing 

 antipneumococcic serum therapy. 



Under existing circumstances, it is therefore advisable to utilize 

 some method for selecting only chill-free concentrates for clinical 

 use. Lots found by preliminary tests to possess this unwanted 

 property may be reprocessed, with particular attention paid to 

 solubilities at various hydrogen ion concentrations. 



Potency Tests 

 In the manufacturing laboratory, the determination of the an- 

 tibody content of antipneumococcic serum is of economic impor- 

 tance in measuring the response of animals during the process of 

 immunization and in selecting serum suitable for therapeutic use. 

 In the clinic it is essential to know the potency of the preparation 

 being used in order to obtain more uniform dosage and to estimate 

 its effectiveness. Standardization of antipneumococcic serum in- 

 volves difficulties not encountered in the assaying of such biological 

 products as diphtheria and tetanus antitoxins. Progress has been 

 made, however, and, as Park and Cooper 1057 ** observed, although 

 the unit of pneumococcal antibody cannot be so accurately esti- 

 mated as the diphtheria antitoxic unit, the present standard suf- 

 fices for therapeutic purposes. 



IN vivo TESTS 



During the development of methods for standardizing antipneu- 

 mococcic serum, both in vivo and in vitro tests have been utilized. 

 The former have included procedures for determining the protec- 

 tive and the therapeutic qualities of serum, and the latter have 

 been concerned with estimating the content of antibodies demon- 

 strable by serological reactions. 



Early animal tests. Washbourn 1487 injected intraperitoneal^ 

 into rabbits mixtures of measured amounts of serum and a quan- 

 tity of culture representing ten times the minimal fatal dose. A 



