CHAPTER XIII 

 BACTERIAL VACCINES 



IN this chapter a method for preparing bacterial vaccines will be 

 described, the general discussion of vaccine therapy, with the special 

 technic for preparing cow-pox vaccine, rabies vaccine, tuberculin, and 

 other special vaccines, being taken up in Chapter XXIX. 



Definition. Bacterial vaccines are "sterilized and enumerated sus- 

 pensions of bacteria which furnish, when they dissolve in the body, sub- 

 stances which stimulate the healthy tissues to a production of specific 

 bacteriotropic substances which fasten upon and directly or indirectly con- 

 tribute to the destruction of the corresponding bacteria" (Wright). 



TECHNIC FOR PREPARING BACTERIAL VACCINES 



Bacterial vaccines are made (1) By procuring the infected ma- 

 terial; (2) by preparing pure cultures of the bacteria that are to be 

 attacked; (3) by making suspensions of these in saline solution, adding 

 a preservative, and placing in proper containers. 



1. Procuring Infected Material. Various precautions, according 

 to existing circumstances, should be taken to avoid contamination and 

 to secure material that is truly representative of the focal secretions. 

 For instance, pus should be collected from an abscess cavity or sinus 

 after the surrounding tissues have been cleansed with dilute tincture of 

 iodin, for if we secured a culture of the relatively harmless Staphy- 

 lococcus epidermidis albus from the skin instead of the Staphylococcus 

 aureus, which may be the cause of infection, our vaccine will have little 

 or no value. 



Nasal secretion may be secured after cleansing the nasal orifice with 

 soap and warm water, passing a sterile cotton swab through a nasal 

 speculum, and rubbing the surfaces of the lower turbinates and septum 

 lightly. 



An ear should be cleansed, the excess of secretions removed with 

 sterile swabs, and the culture be made of pus from the infected tissues. 

 Various saprophytes quickly gain admission and grow in the necrotic pus> 

 whereas the infecting bacterium is more likely to be found in the tissues. 



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