ABSTRACT
Variola virus (VARV) is the causative agent for a once feared infectious disease of humans, commonly known as smallpox. The disease is also known by the Latin names Variola or Variola vera, a derivative of the Latin word “varius” meaning spotted, or “varus” meaning pimple. The term “smallpox” was rst introduced in Europe in the fteenth century to distinguish variola from the “great pox” (syphylis). In humans, smallpox is characterized by the formation of a maculopapular rash followed by raised uid-lled blisters on the skin of humans. Of its two forms variola major and variola minor (caused by two variola virus subtypes), variola major is a more serious disease with an average mortality rate of 30-35%, leaving characteristic facial scars in 65-80% of survivors; variola minor is a milder form (also known as alastrim, cottonpox, milkpox, whitepox, and Cuban itch) with a mortality rate of about 1% of its victims. It is estimated that smallpox disease has caused more human casualties than all other infectious diseases combined [1].
