History

Long before the causes of disease were known and long before the processes of recovery were understood, an interesting thing was observed: if people recovered from a disease, rather than succumbing to it, they appeared to be immune from a second bout with the same illness. Perhaps it was these types of observations that led the Chinese to try to prevent smallpox-a deadly disease characterized by pus-filled blisters-by exposing uninfected individuals to matter from smallpox lesions. This process, known as “variolation,” took a variety of forms. ...Continue reading »