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Smallpox: Basic Information


Smallpox is a virus (germ) that causes a high fever and a rash with draining lesions over the whole body. No person in the world has been diagnosed with smallpox since 1977. For that reason, vaccination for smallpox was discontinued in all countries. Adults vaccinated before 1980 do not have immunity.

Is smallpox spread from person to person?

Yes. This infection is very contagious. When someone with smallpox breathes or coughs the germ is spread into the air. A non-infected person gets the infection by breathing the germ into his/her lungs. The infection can also be spread by skin-to-skin contact with the rash or items contaminated by the rash such as sheets, towels, and clothes.

How will I know if I was exposed to smallpox?

You may have been exposed at the location where the germ was intentionally released. You may also be exposed by being close to a person who has smallpox (within 6 feet).

How soon will the symptoms develop (incubation period)?

Symptoms may start within 7-17 days after exposure. Infected persons are not contagious until the rash appears.

How is the infection treated?

There is no medicine to treat smallpox infection. The doctor may order medicine to control the fever and to keep the person calm and more comfortable.

How is the infection prevented?

There is a limited supply of vaccine available in the U.S. If a smallpox outbreak is confirmed the federal government will release the vaccine to that area.

How will I know if I need to be vaccinated?

If you were in the location where the germ was originally released or if you were exposed to a person who developed the symptoms (fever and rash) you will be offered the vaccination.

How will I know where to go to get the vaccination?

When the vaccine becomes available, the local health department will provide information, by local radio and television, about where to get the vaccine.

Do people get sick from the vaccination?

Complications can occur but are not common. An information sheet will be provided at the time of vaccination that will tell you about possible vaccination reactions.

What can I do to keep from getting infected?

In the event of a smallpox outbreak the most important thing you can do is to stay home. The local health department may ask you to wear a mask over your nose and mouth if you go out. Listen to the local radio or television for instructions from your local health department. Do not go to the hospital emergency room unless you are sick.