

DIPHTHERIA ANTITOXIN 



265 



3. Another method is to inoculate sub-cutaneously every 2 or 3 days for 

 3 weeks quantities of toxin increasing from 25-150 c.c. until about a litre 

 has been injected. The animal is bled 12 days after the last inoculation 

 of toxin. 



(iii) Horses may also be immunized by inoculating them with a mixture 

 of antidiphtheria serum and toxin (Babes, Madsen and Dreyer, Park). The 

 yield of antitoxin is good and the method is more rapid than the iodine 

 terchloride method (Park). 



The following table shows the details of an experiment by Martin. 

 Inoculations twice a week. Toxin killed guinea-pigs weighing 500 grams in 36 hours 

 in doses of O'l c.c. Antidiphtheria serum contained 200 units per c.c. 



1st inoculation, - 25 c.c. serum + 25 c.c. toxin. 



2nd 



3rd 



4th 



5th 



6th 



7th 



8th 



9th 



10th 



llth 



12th 



13th 



14th 



15th 



10 + 25 



25 c.c. pure toxin. 



40 



60 



80 

 100 

 150 

 200 

 250 

 300 

 350 

 400 

 450 

 500 



5. Serum therapeutics. 



Antitoxin. 



Behring and Kitasato in 1890 were the first to demonstrate the antitoxic 

 properties of the blood of animals immunized against diphtheria. 



These observers found that the blood of immunized animals had the property of 

 destroying diphtheria toxin both in vivo and in vitro ; that this property was also 

 present in the serum of blood deprived of all cellular elements ; and that the serum 

 was both therapeutic and prophylactic when used on rabbits and guinea-pigs intoxi- 

 cated with diphtheria toxin or inoculated with living diphtheria bacilli. 



Having established these facts Behring, Ehrlich, and their collaborators turned 

 their attention to the application of antidiphtheria serum to the treatment of 

 human diphtheria (Behring, Ehrlich, Boer, Wassermann, Rossel). But. the serum 

 treatment of diphtheria did not become an accomplished fact in medical practice 

 until after the Congress of Hygiene at Buda-Pesth in 1894 when Roux and Martin 

 communicated a summary of the work they had carried out during the years 1891-4. 



(a) Preparation of the serum. 



The horse is chosen as the source of antitoxin for these reasons, viz. : 

 Horse serum, even in large doses, is innocuous to man and to the lower 

 animals ; horses withstand the action of diphtheria toxin very much better 

 than other animals ; lastly, very large quantities of serum are available 

 (Roux ; Nocard and Martin). 



The immunization of the horse which is carried out as described above 

 generally occupies about 3 months. In practice toxin is inoculated in gradu- 

 ally increasing doses until some 1000-1500 c.c. have been administered : the 

 final inoculations should consist of quantities of 150-200 c.c. 



The animal is bled 8-10 days after the date of the last inoculation : about 

 6 litres of blood are withdrawn and a further quantity may be taken a few 

 days later. It is best to bleed the horse from the jugular vein according to 



