There is a vaccine to prevent smallpox. The vaccine is made from a virus called vaccinia, which is another "pox"-type virus related to smallpox. The vaccine helps the body develop immunity to smallpox. The vaccine does not contain the smallpox virus and cannot cause smallpox.

  1. Getting smallpox vaccine before exposure will protect about 95 percent of people from getting smallpox.
  2. Vaccination within three days of exposure will prevent or significantly lessen the severity of smallpox in the vast majority of people.
  3. Vaccination four to seven days after exposure likely offers some protection from disease or may modify the severity of disease.