344 



BIOLOGY AND HUMAN LIFE 



At present the term vaccination is used to designate any process by 

 which active immunity is induced artificially. There are three types: 



1. The use of living bacteria, as in smallpox vaccination. 



2. The use of dead bacteria, as in antityphoid vaccination. 



Kansas 200 



Washington 172 



Oregon 144 



Indiana 141 



Mississippi 136 



Minnesota US 



Wisconsin 101 



Los Angeles 



Ohio 96 



MichiK^n 82 



Virginia 6S 



Alabama 5-3 



Louisiana 54 



Calif. 44 



Vt. 28 



South Carolina 22 



District of Columbia 14 

 Maryland 10 



fl Connecticut 9 

 New Jersey 2.7 

 New York 2.6 



1922 1923 1924 



Fig. 162. Vaccination and smallpox 



The bars show the relative amount of smallpox (number of cases per 100,000 of 

 population) in nineteen states and the District of Columbia in 1915-1920. At the 

 bottom are the six areas in which compulsory vaccination prevails. At the top are 

 seven states in which there is no compulsory vaccination, but rather opposition to 

 vaccination in many regions. In the middle group are states in which conditions 

 seem to be getting worse; general vaccination is not enforced, or is opposed, in these 

 states. On the right is a graph to show increase in the number of smallpox cases in 



four American cities during recent years 



3. The use of toxin, as in diphtheria vaccination by means of a mix- 

 ture of toxin and antitoxin in certain proportions. The antitoxin is a 

 protective agent, while the toxin stimulates the protoplasm of the child 

 to produce its own antitoxin. 



262. Biological tests of disease. It is often of advantage to 

 know whether a person is already suffering from a given disease. 

 Very often an early diagnosis may make the difference between 



