In 1796 Edward Jenner, an English country doctor, noticed that milkmaids who suffered from cowpox appeared resistant to smallpox. He pioneered "vaccination" using material from the pustules of cows suffering from the related virus. It was the most significant breakthrough in the treatment and prevention of infectious disease at the time. View the following video about Edward Jenner's discovery:

Edward Jenner-Discovery. Accessed at https://www.youtube.com/watch?v=l_3dcY_cwN0 on September 13, 2016.

1. How would you summarize Edward Jenner's accomplishments?
2. All medical procedures, including vaccination, carry some risk. How much risk do you feel is acceptable? Should that risk be balanced between the individual and the general public, or is it more important to protect one over the other?

Conduct some independent research on the term "herd immunity". How does it work and what happens when herd immunity breaks down?