Smallpox, a highly contagious disease, is unique only to humans. The smallpox virus is caused by two virus variants called Variola major and Variola minor. Variola major is the more deadly form of the virus; it usually has a mortality rte of 20-40 percent of those that are infected with the virus. Variola minor on the other hand is much less severe and only kills 1% of its victims. Neither of the Variola's are bugs that you want to get. Avoid them at all costs!
Due to ulcerations of the cornea, many survivors of the smallpox virus are left in one or both of their eyes. Often times they will also have constant skin scarring. Over the 20th century the smallpox virus was responsible for an estimated 200-450 million deaths. After successfully completing several vaccination campaigns the World Health Organization(WHO) in 1979 stated that smallpox virus had been eradicated. Cultures of the virus are always kept at the Disease Control and Prevention which is located in the United States of America, as well as in the Institue of Virus Preparations that is in Siberia, Russia. After 1970 the vaccination was stopped in most places of the world, as the risks of the vaccination include death, among other side effects that aren't meant to joke around with.
After the anthraz attacks on the United Sates in 2001, there have been several concerns that smallpox has/will resurface and possibly become a virus for us in bioterrorism. These concerns have in turn raised more concerns about the availability of vaccine stocks. The concerns are soo great in fact that, President George W. Bush of the U.S.A. has ordered all of his American military personnel to be vaccinated against smallpox and has implemented a voluntary program for vaccinating emergency medical personnel.