152 IMMUNE SERA 



instances been injected with antidiphtheric horse 

 serum at short and long intervals, without, so far 

 as we are aware, causing death. Certain serums, 

 for example, the anti tubercle serum of Maragliano 

 and the antirheumatic serum of Menzer, are habit- 

 ually used by giving injections at intervals of days 

 or weeks. It may, of course, be pbjected that 

 possibly these injections are so spaced as to produce 

 antianaphylaxis. If a person had once before had 

 an injection of horse serum, would it be safe, say 

 some months, or a year, or several years later, to 

 give him another injection of horse serum? Or if 

 a child had been immunized against diphtheria 

 would it be safe to repeat the injection a year 

 later if the child were again exposed? The exper- 

 ience of clinicians is practically unanimous in show- 

 ing that such second injections need not be feared. 

 Even if the results obtained in guinea pigs were 

 applicable to man, a subcutaneous injection in man 

 comparable to the amount required to produce 

 sickness in a guinea pig would be over 200 cc. 

 To date about twenty cases of sudden death follow- 

 ing the injection of horse serum have been recorded 

 in the literature, and while this undoubtedly does 

 not represent all the cases that have occurred, the 

 total number is insignificant when compared to the 

 enormous number of such injections already made. 

 In New York City, in over 50,000 persons injected, 

 but two deaths attributed to the serum injection 



