ANATOMY

Detailed explanation-1: -Two forms of the disease are recognized, variola minor with a mortality rate of approximately 1%, and the more common variola major with a mortality rate of 30%.

Detailed explanation-2: -Death. While an infection of the variola minor virus would lead to death with a probability of less than one percent, the case fatality rate of the variola major virus has been estimated to be around 30 percent.

Detailed explanation-3: -Historically, the vaccine has been effective in preventing smallpox infection in 95% of those vaccinated. In addition, the vaccine was proven to prevent or substantially lessen infection when given within a few days of exposure.

Detailed explanation-4: -Death usually occurred within eight to 16 days. Variola minor had similar symptoms but was much less deadly, with death rates around 1 percent.

Detailed explanation-5: -Death was due to systemic shock (body-wide infection) and toximemia (toxins in the blood). Smallpox is a very contagious disease, with secondary attacks affecting up to 80% of household contacts. Often, people who survived the disease had long-term problems, such as blindness and severe scarring.