This information is provided for educational purposes only and should not be construed as medical advice.

About the Disease
Smallpox is a serious, highly contagious, and sometimes fatal infectious disease. There is no specific treatment for smallpox disease, and the only prevention is vaccination.

Live Virus Vaccines and Vaccinia
The vaccinia virus is the "live virus" used in the smallpox vaccine. It is a "pox"-type virus related to smallpox. When given to humans as a vaccine, it helps the body to develop immunity to smallpox. The smallpox vaccine does not contain the smallpox virus.

How many people would have to get smallpox before it is considered an outbreak?
One confirmed case of smallpox is considered a public health emergency.

Is smallpox contagious before the smallpox symptoms show?
A person with smallpox is sometimes contagious with onset of fever (prodrome phase), but the person becomes most contagious with the onset of rash. The infected person is contagious until the last smallpox scab falls off.

How is the vaccine given?
1. The smallpox vaccine is not given with a hypodermic needle. It is not a "shot," like many vaccinations. The vaccine is given using a bifurcated (two-pronged) needle that is dipped into the vaccine solution. When removed, the needle retains a droplet of the vaccine. The needle is then used to quickly prick the skin 15 times in a few seconds. The pricking is not deep, but it will cause a sore spot and one or two drops of blood to form. The vaccine usually is given in the upper arm.

2. If the vaccination is successful, a red and itchy bump develops at the vaccination site in three or four days. In the first week after vaccination, the bump becomes a large blister, fills with pus, and begins to drain. During week two, the blister begins to dry up and a scab forms. The scab falls off in the third week, leaving a small scar. People who are being vaccinated for the first time may have a stronger "take" (a successful reaction) than those who are being revaccinated.

Normal, Typically Mild Reactions
These reactions usually go away without treatment:

• The arm receiving the vaccination may be sore and red where the vaccine was given.
• The glands in the armpits may become large and sore.
• The vaccinated person may run a low fever.
• The vaccinia virus (the live virus in the smallpox vaccine) may cause rash, head and body aches.
• One out of 3 people may feel bad enough to miss work, school, or recreational activity or have trouble sleeping.

Post-Vaccination Care
After the vaccine is given, it is very important to follow care instructions for the site of the vaccine. Because the virus is live, it can spread to other parts of your the body, or even to other people.

Who Should NOT Receive the Smallpox Vaccine?
(Unless they are Exposed to the Smallpox Virus)

• Expectant mothers?
• People with eczema or atopic dermatitis?
• People being treated for cancer?
• People who are HIV-positive?
• People who have had an organ transplant?

Here's why
Some people are at greater risk for serious side effects from the smallpox vaccine. Individuals who have any of the following conditions, or live with someone who does, should NOT get the smallpox vaccine unless they have been exposed to the smallpox virus. Higher risk conditions are:

• Eczema or atopic dermatitis. (This is true even if the condition is not currently active, mild or experienced as a child.)
• Skin conditions such as burns, chickenpox, shingles, impetigo, herpes, severe acne, or psoriasis. (People with any of these conditions should not get the vaccine until they have completely healed.)
• Weakened immune system. (Cancer treatment, an organ transplant, HIV, or medications to treat autoimmune disorders and other illnesses can weaken the immune system.)
• Pregnancy or plans to become pregnant within one month of vaccination.

• Are allergic to the vaccine or any of its ingredients.
• Are less than 18 years of age.
• Have a moderate or severe short-term illness. (These people should wait until they are completely recovered to get the vaccine.)
• Are currently breastfeeding.
• People living with someone less than a year old.

If someone is exposed to smallpox, is it too late to get a vaccination?
Vaccination within 3 days of exposure will completely prevent or significantly modify smallpox in the vast majority of persons. Vaccination 4 to 7 days after exposure likely offers some protection from disease or may modify the severity of disease.

How long does a smallpox vaccination last?
Past experience indicates that the first dose of the vaccine offers protection from smallpox for 3 to 5 years, with decreasing immunity thereafter. If a person is vaccinated again later, immunity lasts longer.

Again, people who have been directly exposed to the smallpox virus should get the vaccine, regardless of their health status.

Don't Hesitate!
If offered the smallpox vaccine, individuals should tell their immunization provider if they have any of the above conditions, or even if they suspect they might.

Benefit of Vaccine Following Exposure
Vaccination within 3 days of exposure will prevent or significantly lessen the severity of smallpox symptoms in the vast majority of people. Vaccination 4 to 7 days after exposure likely offers some protection from disease or may modify the severity of disease.

Smallpox Vaccine Availability
Routine smallpox vaccination among the American public stopped in 1972 after the disease was eradicated in the United States. Until recently, the U.S. government provided the vaccine only to a few hundred scientists and medical professionals working with smallpox and similar viruses in a research setting.

• After the events of September and October, 2001, however, the U.S. government took further actions to improve its level of preparedness against terrorism. One of many such measures-designed specifically to prepare for an intentional release of the smallpox virus-included updating and releasing a smallpox response plan. In addition, the U.S. government ordered production of enough smallpox vaccine to immunize the American public in the event of a smallpox outbreak. Right now, the U.S. government has access to enough smallpox vaccine to effectively respond to a smallpox outbreak in the United States.

SMALLPOX VACCINE SAFETY
The smallpox vaccine is the best protection you can get if you are exposed to the smallpox virus. Anyone directly exposed to smallpox, regardless of health status, would be offered the smallpox vaccine because the risks associated with smallpox disease are far greater than those posed by the vaccine.

There are side effects and risks associated with the smallpox vaccine. Most people experience normal, usually mild reactions that include a sore arm, fever, and body aches. However, other people experience reactions ranging from serious to life threatening. People most likely to have serious side effects are: people who have had, even once, skin conditions (especially eczema or atopic dermatitis) and people with weakened immune systems, such as those who have received a transplant, are HIV positive, are receiving treatment for cancer, or are currently taking medications (like steroids) that suppress the immune system. In addition, pregnant women should not get the vaccine because of the risk it poses to the fetus. Women who are breastfeeding should not get the vaccine. And people less than 18 years of age and those allergic to the vaccine or any of its components should not receive the vaccine.

In the past, about 1,000 people for every 1 million people vaccinated for the first time experienced reactions that, while not life-threatening, were serious. These reactions included a toxic or allergic reaction at the site of the vaccination (erythema multiforme), spread of the vaccinia virus to other parts of the body and to other individuals (inadvertent inoculation), and spread of the vaccinia virus to other parts of the body through the blood (generalized vaccinia). These types of reactions may require medical attention. In the past, between 14 and 52 people out of every 1 million people vaccinated for the first time experienced potentially life-threatening reactions to the vaccine. Based on past experience, it is estimated that 1 or 2 people in 1 million who receive the vaccine may die as a result. Careful screening of potential vaccine recipients is essential to ensure that those at increased risk do not receive the vaccine.

This information is provided for educational purposes only and should not be construed as medical advice.

TOP of PAGEHOME PAGE