238 PASSIVE IMMUNIZATION 



instilled into the conjunctival sac every two hours. As a prophylactic dose in this 

 disease, 100 units suffice. 



Merck also prepares a vaccine of dead pneumococci in doses of i c.cm. which further 

 aid in the treatment of pneumococci infections. One cubic centimeter of such dead 

 pneumococci can be administered for the prophylaxis of ulcus serpens. 



4. Pest Sera. A large number of pest sera are in use. 



a. The Paris serum (Yersin) produced at Pasteur Institute by immunization of 

 horses with dead and later on living bacilli. 



b. The Bern serum of Tavel employs the same principles. 



c. Lustig's Serum. For this serum, horses are immunized with the pest-nucleo- 

 proteids. Pest cultures are broken up by i per cent, of potassium hydroxide and from 

 this, by the addition of acetic acid, the nucleoproteid is precipitated and then suspended 

 in salt solution to serve as antigen. 



d. Serum of Terni-Bandi is prepared by the immunization of donkeys and sheep 

 with natural pest aggressins. 



e. Serum of Markl is supposedly an antitoxic serum prepared by immunization 

 with nitrates of old pest bouillon cultures. 



All the above sera contain agglutinins, precipitins, bacteriotropins and ambocep- 

 tors; the serum of Terni-Bandi contains aggressin amboceptors, that of Markl, anti- 

 endotoxins. 



The sera are tested for their anti-infectious properties in animals such as guinea- 

 pigs, rats, mice. Markl also estimates the toxin neutralization power of his serum. 



The Paris serum comes either in dry form or in bottles containing 20 c.cm. without 

 any preservatives. Ten to 20 c.cm. should suffice as a prophylactic injection, although 

 Martini advises 100 c.cm. at least. The period of protection is short, averaging about 

 fourteen days. 



Prophylactic injection is advisable in those instances where an immediate protection 

 is necessary, like the inoculation of physicians and nurses attending pest patients. 

 Under all other circumstances either active immunization or the simultaneous method 

 of Shiga should receive the preference. 



For the treatment of pest infections, Calmette and Salimbeni advise intravenous 

 administration of 20 c.cm. and two subcutaneous injections of 40 c.cm. each all to be 

 given on the first day; on the second day two similar subcutaneous injections; and if 

 the case is of a severe nature, the dose may be doubled. The results are variable. 



From comparative studies, it seems that Lustig's serum is somewhat weaker than 

 the Paris serum. The sera of Terni-Bandi and Markl have not been sufficiently 

 employed, so that opinion is reserved. 



5. Tuberculosis Sera. The best known and most studied are those of Maragliano 

 and Jarmorek. 



a. Serum of Maragliano is prepared by Maragliano's institute in Genoa from horses 

 which are immunized for about six months with the soluble substances of tubercle ba- 

 cilli. The favorable action of the serum is reported on, especially by Italian authorities. 



b. Serum of Marmorek is prepared in the laboratory of Marmorek, at Paris-Neuilly, 

 by the immunization of horses with the so-called "primitive" tubercle bacilli, i.e., 

 young tubercle bacilli whose acid-fast character is still very slight or entirely absent. 

 When the horses have attained a high grade of immunity, they receive injections of 

 various strains of pure cultures of streptococci obtained from the sputum of tubercu- 

 lous patients. The serum of these animals is, therefore, antituberculous and at the 

 same time polyvalent antistreptococcic (a double serum), serving against the mixed 

 infections. 



This serum is administered daily, either subcutaneously 5 to 10 c.cm. or per rectum 



