IMMUNITY 77 



then diluted so that each cubic centimeter will contain 

 exactly a certain number of million bacteria, after which 

 it is ready for injection. Such a suspension is spoken of 

 as a "bacterial vaccine." The doses of the different 

 vaccines vary. In the case of staphylococcus vaccine 

 the ordinary dose is from 250,000,000 to 500,000,000. 

 Gonococci are usually given in much smaller doses, 

 namely, from 15,000,000 to 50,000,000. The dose of 

 typhoid vaccine is from 500,000,000 to 1,000,000,000. 

 The vaccines are usually given in several doses, injections 

 being made from five days to a week apart. 



At the present time treatment either by specific sera 

 or by bacterial or other vaccines is employed in 



Diphtheria. Antitoxic serum therapeutically. Serum 

 or toxin injections for immunization. 



Tetanus. Antitoxic serum, both therapeutically and 

 for immunization. 



Epidemic Cerebrospinal Meningitis. Specific serum 

 therapeutically. Vaccines have been used for immuniza- 

 tion. 



Typhoid Fever. Vaccines for immunization. Neither 

 serum nor vaccines of use therapeutically. 



Cholera. Specific serum has been used therapeutically; 

 results indifferent. Vaccines used for immunization. 



Plague. Vaccines have been tried for immunization. 



Tuberculosis. Neither therapeutically nor for immuni- 

 zation have either serum or vaccine yielded satisfactory 

 results. 



Pneumonia. Serum therapeutically has apparently 

 been of value in certain types of cases. Vaccines have not 

 yielded satisfactory results. 



