HLTH 385W Chapter Notes - Chapter 7: Smallpox, Vaccinia, Smallpox Vaccine
12 Jul 2018
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Course
Professor
History of Smallpox - Geddes
The Disease
● Smallpox is an infectious disease caused by the variola virus
○ Variola major - causes major smallpox
○ Variola minor- causes minor smallpox (rarely life threatening)
● Related to other poxviruses, such as cowpox and vaccinia virus
● Enters the human body through the respiratory tract and spreads through the airborne
tract
● Causes lesions on the mouth and skin
● Universal vaccination against smallpox was discontinued in the early 1970s when it
seemed like it was about to be eradicated
Early history
● The origin is unclear - but seems to be when humans started to be organized into
communities and began to travel
● Smallpox is found in egyptian mummies
● Could have been transferred from egypt to India, then to China, then to Japan
● Came into Europe periodically but was only established when the population increased
and movement became more active during the crusades
● It killed up to 30% of those infected
● Introduced into Americas in 1520
● In early 1500’s, It was introduced into the Caribbeans by Spanish armies, spread to
Mexico, Peru, Brazil → caused widespread death in the Incas
● In the 18th century, it was widespread pretty much everywhere except for Australia
Smallpox in Europe
● Smallpox was always present, causing widespread death and fear
● There were large outbreaks of smallpox in England in 18th century
○ 80% of the deaths in children < 5 years old
● A reduction in the incidence in Europe happened in 19th century, after vaccination
became generally available
Smallpox Vaccination
● Smallpox vaccine contains the vaccinia virus (cause of infection in cattle)
● First ever to be shown to be effective in preventing an infection
● Edward Jenner introduced immunization with material from cowpox lesions
○ He argued that farm workers appeared to be immune to smallpox
○ Theorized that it is because of the previous cowpox infection and that cowpox
could be transmitted
○ He tested it on a milkmaid
● The church widely opposed the practice of vaccination, but the practice still became
accepted
○ Still a controversy
● Requires 3 yearly boosters to maintain its efficacy
● Was determined to be reasonably safe and efficacious
Document Summary
Smallpox is an infectious disease caused by the variola virus. Variola minor- causes minor smallpox (rarely life threatening) Related to other poxviruses, such as cowpox and vaccinia virus. Enters the human body through the respiratory tract and spreads through the airborne tract. Causes lesions on the mouth and skin. Universal vaccination against smallpox was discontinued in the early 1970s when it seemed like it was about to be eradicated. The origin is unclear - but seems to be when humans started to be organized into communities and began to travel. Could have been transferred from egypt to india, then to china, then to japan. Came into europe periodically but was only established when the population increased and movement became more active during the crusades. It killed up to 30% of those infected. In early 1500"s, it was introduced into the caribbeans by spanish armies, spread to. Mexico, peru, brazil caused widespread death in the incas.
