How is smallpox treated?

There are no drugs to treat smallpox once a person develops the disease. (Drugs can be given to relieve some of the cold and flu symptoms and other illnesses that might arise in addition to the smallpox.) Instead, a vaccine is given to prevent people from contracting the disease in the first place.

Currently, only military personnel who might be exposed to smallpox as a biological weapon of warfare and U.S. healthcare workers ("first responders") are offered the vaccine. However, enough vaccine has been manufactured to inoculate every man, woman, and child in the United States should a bioterrorist attack with smallpox occur.

If there is an outbreak of smallpox, vaccination within three days of exposure will completely prevent or significantly modify the severity of disease in most patients. Vaccination within four to seven days of exposure will likely offer some protection against the disease. The vaccine provides protection from smallpox for three to five years.

How is the smallpox vaccine given?

A bifurcated (two-pronged) needle that has been dipped into the vaccine solution is used to prick the skin of the upper arm several times. The pricking is not deep, but will cause a sore spot and one or two droplets of blood to form. If the vaccination is successful, red, itchy bumps develop at the vaccination site. This is followed a few days later by a blister, and finally a scab that falls off about three weeks later.

Last reviewed by a Cleveland Clinic medical professional on 01/17/2017.


  • Centers for Disease Control and Prevention. Smallpox Accessed 1/24/2017.
  • National Institute of Allergy and Infectious Diseases. Smallpox Accessed 1/24/2017.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy