IMMUNITY, J'ACCINES AND SERA 599 



Some medical officers use a tube of asbestos cloth surrounded by 

 coKon silicate, the whole placed within a wooden or bamboo lube. 

 Others have found thermos flasks useful. 



TABLii; OF Vaccines and their Doses. 



Vaccine Appt'oxijiia/e Dose 



Acne bacillus 5 million initial, to 20 million 



Acne bacillus with staphylococcus 5 million with 100 million increased 



IJacilius septus 50-500 million 



Cerebro-spinal meningitis 5-10 million initial 



Cholera No. i followed by No 2 



Coli bacil'us 10-25 initial up to 500 million 



Diphtlieria 10-100 million 



Friedliindei's bacillus 50 million initial to 1,000 million 



Gonococcus 25-50 million to 1,000 million 



Micrococcus melitensis 25-250 million 



Pneumococcus 25-500 initial to 500 million 



Staphylococcus 100-5,000 million 



Streptococcus Up to 500 million 



Typhoid 500-1,000 million. (Broth cultures) 



Dysenteiy In four strengths, for immunizing and 



curative in chronic conditions 



Mallein f 10-15 minims in humans 



1 I c.c. for diagnosis in animals 



Plague 75-80 million or i c.c. 



Vaccines are : — 



(i) Killed or attenuated org^anisms with or without toxins. Such 

 are known as Bacterial Emulsions. 



(2) The toxins only as in Mallein. 



(3) The fluids of animals suffering from an infectious disease, e.g., 

 calf lymph. 



(4) Sensitized vaccines. 



Antitoxic Sera are usually obtained from the horse. A healthy one 

 is reared, tested for tuberculosis and glanders, inoculated with atten- 

 uated serum, later with increasing doses of virulent toxin until a higii 

 degree of tolerance has been obtained. The horse rests a few days, 16 

 to 20 pints of blood are then drawn ofif from the jugular vein into sterile 

 flasks, the serum is decanted after coagulation and mixed with anti- 

 septic, it is tested for sterility and toxicity and then standardized. A 

 standard dose is sufficient to neutralize a given minimal lethal dose 

 in an animal of known weight. 



A unit dose of antitoxin will exactly neutralize 100 minimal lethal 

 doses. In diphtheria a unit dose of loxin will kill a 250 grm. guinea- 

 pig in four days; this is considered as a minimum lethal dose. The 

 former or unit dose of antitoxin will neutralize the latter or animal 

 lethal dose and prevent symptoms. 



Sera have been used for diphtheria, tetanus and bacterial dvsentery> 

 with high value, and in snake bite and plague with some value, iXx. 

 cholera with little value, and in tuberculosis and leprosy with doubtful 

 value. 

 18 



