792 PASSIVE IMMUNIZATION SERUM THERAPY 



two weeks, from six to eight liters of blood being removed at each sitting. The serum 

 is separated and preserved with trikresol. Recent investigations indicate that trikresol 

 may be partly responsible for paralysis of the respiratory centers, and at present every 

 effort should be made to collect and market the serum in a strictly aseptic manner, so that 

 none or but very little preservative is required. 1 Efforts are being made at present to 

 discover an efficient volatile antiseptic that may be driven off by warming the serum 

 at body temperature. 



Rapid Method of Amoss and Wollstein. 2 These investigators have recently advo- 

 cated a rapid method of immunization consisting in inoculating alternately several 

 strains of living meningococci and parameningococci and the autolyzed products 

 of each, by which a potent polyvalent serum may be produced in eight to twelve 

 weeks instead of in the ten months required by the subcutaneous method. In the 

 preparation of a polyvalent serum a twenty-four-hour agar slant culture of meningo- 

 cocci is removed with 2 c.c. of salt solution and 0.1 c.c. suspended in 15 c.c. of salt 

 solution and injected very slowly into the circulation of a horse. The temperature is 

 taken hourly and should not rise over 3 C.; twenty-four hours later 0.2 c.c. of sus- 

 pension, and on the third day 0.3 c.c. are given. After the lapse of seven days a 

 series of three injections of living parameningococci are given in doses of about 

 0.3 c.c. of the emulsion or sufficient to give a temperature reaction of about 2.5 to 

 3 C. After a lapse of seven days three intravenous injections of an autolysate 

 composed of equal parts of autolysate of meningococci and parameningococci are 

 given. A series of three injections of living meningococci and parameningococci 

 follow in doses which may be run up to 0.6 c.c. of emulsion, with every third series 

 consisting of injections of the mixed autoly sates; after ten to twelve weeks a potent 

 serum is generally produced. In order to make the serum as polyvalent as possible 

 a large number of strains of meningococci and parameningococci should be used. 



Severe reactions due to hypersensitiveness of the horse to the meningococci or 

 its products are especially likely in the first dose of each series after three or four 

 series of injections have been given. In order to desensitize, a portion of the first 

 injection of each series is injected intravenously, and two hours later the remainder 

 of the dose is given. Danger due to agglutinated cocci is lessened by diluting the 

 dose in 15 to 20 c.c. of salt solution and injecting very slowly. 



Standardization of Antimeningococcus Serum. An accurate method of stand- 

 ardizing antimeningococcus serum has not as yet been devised. In the selection of a 

 serum physicians must, therefore, be guided by the reputation of the manufacturers. 



An antimeningococcic serum of high antibody content has antitoxic, bacterio- 

 tropic, and bactericidal properties. Kraus and Dorr consider that the chief function 

 of the serum is antitoxic; Flexner and Jobling, Neufeld, Jochmann, and Wassermann 

 believe that its bacteriotropic properties are its most important qualities. 



The following methods for testing an immune serum are in use or have been 

 advocated; none of them is, however, sufficiently reliable to serve as a definite 

 measure of antibody content or of curative value; two of them, the bacteriotropic and 

 the complement-fixation test, are most widely used in laboratories for the purpose of estimat- 

 ing the antibody content of a serum. 



1. Bacteriotropic Titration. While the antimeningitic serum was being prepared 

 at the Rockefeller Institute, Jobling* used the opsonic test in standardization as the 

 method of choice, on account of the part taken by specific opsonins in promoting 

 recovery from meningococcus infections. As a definite and suitable standard of 

 strength Jobling has suggested that a serum be accepted as satisfactory when it shows 



1 Hall, W.: Bull. No. 91, Hyg. Lab., U. S. P. H. S., 1914. 



2 Jour. Exper. Med., 1916, 23, 403. 3 Jour. Exper. Med., 1909, xi, 6, 4. 



