The Gold Star on the Story, the Bright Shining Moment to Lift You Up

The word vaccination that we use now for all vaccines is because of smallpox. Jenner decided to call this practice vaccination, Vaca, meaning cow in London. In the 20th century, smallpox killed over 300 million people. That's more than all 20th century wars combined. It's also the population of the United States of America.