VACCINES IN PROPHYLAXIS OF DISEASE 181 



it never became popular among the masses, as 

 death frequently followed the inoculation. In 

 the same year (1721) Dr. Zabdiel Boylston, of 

 Boston, introduced inoculation in America. 

 During this year an epidemic of smallpox was 

 present in Boston. There was much opposition 

 to inoculation and the practice ceased on the 

 discovery of vaccination. 



Prior to this discovery, it had long been 

 known that an attack of cowpox conferred im- 

 munity to smallpox. This fact had been ob- 

 served by those engaged in dairying and the 

 care of cattle in various parts of the world. 

 Dr. Edward Jenner who lived in Sodbury, Eng- 

 land, grasped the significance of this fact and 

 on May 14, 1796, he vaccinated his first case, 

 James Phipps, aged eight years, using serum 

 taken from a cowpox vesicle on the hand of a 

 dairymaid, Sarah Nelmes ; and on July first, he 

 proved the immunity of the boy to smallpox by 

 his failure in repeated attempts to give him 

 smallpox, either by inoculation or by exposure 

 to the disease. The experiment was repeated 

 many times in other subjects; and finally, in 

 1798, Jenner published an account of his work: 

 "An inquiry into the causes and effects of 



