192 ACTIVE IMMUNIZATION 



surface growth of the bacilli can take place. Every two to three 

 days the cultures should be shaken, so that new crops of the organisms 

 can develop in contact with the air, the older ones going to the 

 bottom. 



After a six weeks' growth has been obtained, the purity of the 

 culture is examined by plating out a small amount on agar. The 

 material is sterilized for one or more hours at 65 C., treated with 

 carbolic acid to the point of 0.5 percent., and finally filled into small 

 vials of 30 c.c. capacity. 



Dose. The ordinary dose for adult males is 3 to 3.5 c.c.; for adult 

 females, 2 to 2.5 c.c.; for children more than ten years old, 1 c.c., and 

 for smaller children, 0.1 to 0.5 c.c. Much larger quantities, however, 

 can be employed without harm, and Haffkine himself has injected as 

 much as 20 c.c. A second injection is recommended after eight to 

 ten days. The injections are made subcutaneously, with a sterile 

 syringe, into the upper arm (area over the triceps) or the loin, those 

 districts being avoided, as usual, where the skin is tightly bound down. 



Symptoms following Injection. The symptoms following the 

 injection are practically the same as those occurring after an anti- 

 cholera or antityphoid vaccination, and differ considerably in their 

 severity in different people. After twenty-four to forty-eight hours 

 the individuals are usually no longer inconvenienced. 



After the disease has once developed vaccination is of no avail, 

 and in such cases serum treatment should be resorted to (see below) . 

 The combined procedure would suggest itself as being of value when 

 there is reason to think that the person may have already been 

 exposed to the infection or when great danger actually exists. For 

 such purposes Shiga advocates an initial treatment of 0.6 to 1 c.c. 

 each, of antiplague serum and vaccine, which is to be followed after 

 a few days, i. e., after the reaction has disappeared, by a second 

 injection of vaccine alone. The latter is essentially an emulsion of 

 three-day-old agar cultures (incubated at 30 C.), 1 c.c. of physio- 

 logical salt solution being used for each oese of the culture. The 

 emulsion is kept for 30 minutes at 60 C., treated with carbolic acid 

 to the extent of 0.5 per cent., and allowed to stand for twenty-four 

 hours before being used. 



During epidemics Shiga recommends that still larger doses of 

 the vaccine be used, or to vaccinate three times with increasing 

 quantities. 



