The study of poxviruses has a long and distinguished history that includes Jenner s founding work on smallpox vaccination. In the more than 200 years since that time we have seen the remarkable eradication of smallpox. It is difficult to overstate the significance of that achievement. It not only removed a disease that must rate as one of humankind s greatest scourges, but also demonstrated the effectiveness of the general principle of vacci- tion in our battles against disease. This book begins with a review of smallpox and its causative agent, Variola virus. The vaccine used in the...