Smallpox is a viral infection. It is contagious and can be deadly. The disease was eliminated worldwide. This was done through global immunization programs. The last known natural occurring human case was in 1977. Governments have studied its use as a germ-warfare weapon. As a weapon, it would be released in the air. Those exposed could develop the disease. They would then pass it to other people.

Vaccination and Lymph System
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Variola major is the virus that causes the infection. It is spread:

  • Through the airborne droplets of infected saliva
  • Between people who have direct contact
  • Through the handling of contaminated bed linens or clothing