Two forms of smallpo. Historically there have been two forms of the disease. Variola major was the main form of the disease that caused all sorts of medical problems. Variola minor was much less common, much less severe, and only about 1% of all smallpox infections. There hasn't been a smallpox infection in the world since 1978, so you are unlikely to see either of these viruses.
One basic disease. As an eradicated disease, no forms are now present in the wild. Some stored virus is present in research as a hedge against any return. In its day, regular smallpox had two presentations that had higher death rates, including a malignant form and a hemorrhagic (blood breakdown form).
Smallpox. There were 2 clinical types of smallpox. Variola minor was less severe than Variola Major. Smallpox from Variola Minor had a death rate of 1% or less. 90% or > unvaccinated smallpox cases fell under the category of “ordinary Smallpox”. The overall fatality rate for Smallpox was 30%. Malignant (AKA flat) Smallpox made up 5 to 10% of cases, was usually fatal & mostly effected children. >>