DOSAGE OF VACCINES igi 



and then sucking up one- twentieth of i% dahlia in i% formalin to n or 101. 

 Allow the bacteria to settle on the shelf for ten minutes before counting. Count as 

 in making a red count. 



The use of a piece of amber glass in front of an incandescent light 

 enables one to pick up the bacteria more satisfactorily as well as to 

 differentiate bacteria from debris. A counting chamber with a depth 

 of J^o mm. is to be preferred to the ordinary % o mm. chamber as one 

 can begin the count after about five minutes time for settling. 



A satisfactory diluting fluid is that recommended by Callison. It is : Hydrochloric 

 acid 2 c.c., Bichloride of mercury (i to 500 aq. sol.) 100 c.c., and sufficient i% 

 aqueous solution of acid fuchsin to color the diluting mixture a deep cherry red. 

 The diluting fluid should then be filtered. The bichloride forms an albuminate 

 on the surface of the bacteria which promotes rapid sedimentation and the fuchsin 

 stains the bacteria. 



Having determined the strength of the stock vaccine, we should 

 prepare a dilute vaccine for injection. 



This is most conveniently carried out by filling vials with 50 c.c. of salt solution, 

 plugging with cotton, then sterilizing in the autoclave. A sterile rubber cap is now 

 drawn over the mouth of the vial. Sterility is insured by plunging the rubber cap 

 and neck in boiling water. If the stock vaccine showed 5,000,000,000 bacteria per 

 c.c. and we desired to have a vaccine containing 200,000,000 bacteria per c.c., it 

 would be necessary to draw out 2 c.c. of the salt solution by means of a sterile syringe 

 needle inserted through the rubber cap and replace it with 2 c.c. of the bacterial 

 emulsion. Example: In introducing 2 c.c. of a vaccine containing 5,000,000,000 

 bacteria per c.c., we throw in 10,000,000,000 bacteria in a volume equal to 50 c.c. 

 Then each c.c. of the 50 c.c. in the bottle would contain 10,000,000,000 divided by 

 50 or 200,000,000 in each c.c. If we only want a vaccine containing 100,000,000 per 

 c.c. we should only add i c.c. We now add Y% of trikresol to the vaccine in order 

 to insure sterility. (Introduced with syringe, inserting needle through rubber cap.) 

 The syringe is best sterilized by drawing up vaseline or olive oil heated to i5oC., 

 and the neck and rubber cap of the bottle in boiling water. We now draw up the 

 desired dose of bacteria. If glass syringes are used, simply boiling in water suffices. 

 One can purchase ampoules which are sterilized and filled with a standardized 

 emulsion. They are sealed in the flame and labelled with the bacterial content 

 per cc. 



The ordinary doses are: For gonococci, streptococci, pneumococci, 

 and colon vaccines, 5,000,000 to 50,000,000. For staphylococci 



200,000,000 tO 1,000,000,000. 



Wilson gives the following minimum and maximum doses expressed in millions: 

 Streptococcus, 6 and 68. 

 Gonococcus, 45 and 900. 

 Meningococcus, 300 and 900. 



