What is smallpox?

Smallpox is a serious disease caused by a virus - the Variola virus. Before the discovery of a vaccine in 1796, smallpox was common throughout the world. The last case of smallpox in the world was in 1978. The United States stopped routine smallpox vaccinations in 1972, since the side effects from the vaccinations were greater than the risk of getting the disease.

How is smallpox spread?

Smallpox can be spread when an infected person talks, coughs, or sneezes near another person.

What are the symptoms?

  • Symptoms begin to appear within seven to 19 days after being exposed to the virus. The first symptoms may include high fever (above 101° F), feeling tired, headache and backache. One to four days after the first symptoms, the infected person develops a rash that is seen mainly on the face, legs and arms. The rash starts as flat, red sores; over the next two days, these sores fill with pus. The sores begin to form a crust early in the second week of illness and then develop into scabs.
  • The scabs fall off after three to four weeks.

How long is a person with smallpox able to spread the disease?

People with smallpox can not spread the disease until they develop a rash, which may begin on the skin or in the mouth. They are most infectious during the first week of illness because that is when the largest amount of virus is present in saliva. However, they can still spread the disease until all scabs have fallen off (about three to four weeks) of the infected person.

What treatment is available for smallpox?

There is currently no proven treatment for smallpox. Patients with smallpox are given intravenous fluids and medicine for pain and fever. Most patients with smallpox recover, but death occurs in up to 30 percent of cases. If given to people within the first four days of their exposure to smallpox, the vaccine might make illness less severe or possibly prevent it entirely.

What do I do if I have smallpox symptoms?

If you have a severe rash with bumps and fever, please consult a health care provider at once.

When can I be vaccinated?

Smallpox vaccine will be available toward the end of January 2003 to health care providers and those who would respond if smallpox cases occur. Public announcements will be made to direct those first responders to the appropriate facility.

Additional Information for the General Public

CDC Smallpox Information

About the Disease

About the Vaccine

CDC FAQ's about Disease/Vaccine

Additional Information for Health Care Providers

Vaccine Administration


Disaster Preparedness