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