VACCINES IN PROPHYLAXIS OF DISEASE 207 



hours and then gradually subsides, disappear- 

 ing as a rule in 48 to 72 hours. Occasionally 

 the red and swollen area may be quite extensive 

 and extend from above the point of inoculation 

 to the elbow. At times it also extends upward 

 to the axilla, and the lymph nodes may be 

 swollen and tender on pressure. The glandular 

 swelling disappears in twenty-four to forty- 

 eight hours and is never followed by permanent 

 enlargement or suppuration. 



The general reaction varies in its symptoms 

 much more than the local. In children and in 

 many adults it may be entirely absent. The 

 milder form is characterized by a transitory 

 headache and a feeling of weariness, lasting 

 from a few hours to a day. In the average case 

 the mild reaction resembles the feeling of dis- 

 comfort associated with the onset of an attack 

 of influenza. Moderate reactions are those 

 characterized by a rise in temperature, which 

 may reach 101 to 103 degrees F. Moderate re- 

 actions follow about 2*/2 per cent of all doses. 

 General reactions more frequently follow the 

 first than the other two doses. 



Immunity It has not yet been definitely es- 

 tablished how long the immunity induced by the 



