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Smallpox Vaccine


What is the smallpox vaccine?

The smallpox vaccine is an injection given to help prevent smallpox. Smallpox is a disease caused by a virus. The vaccine is effective for about 3 to 5 years.

Who should get the smallpox vaccine?

The vaccine is not part of the usual vaccination schedule because the risk of disease is so low. It is only given to certain people, such as those who would take action during a smallpox outbreak. You can get the smallpox vaccine up to 4 days after you are exposed to the virus. This may prevent a severe infection. You should get the vaccine or booster doses if you are a:

  • Healthcare provider who may treat or be in close contact with those who could have smallpox
  • Laboratory worker who handles the smallpox virus or other pox viruses
  • Military or other staff member who may be sent to areas with smallpox threat

Who should not get the smallpox vaccine?

Talk to your healthcare provider about any of the following. He or she may recommend the vaccine during an outbreak.

  • Children younger than 16 years
  • Anyone who had an allergic reaction to the vaccine or to the antibiotics neomycin, streptomycin, polymyxin B, or chlortetracycline
  • A pregnant female
  • Anyone with immune system problems, leukemia, lymphoma, cancer, HIV, or AIDS
  • Anyone who had a bone marrow or organ transplant
  • Anyone who uses medicines that weaken the immune system, such as steroids, radiation, or cancer medicines

What happens when I receive the smallpox vaccine?

The smallpox vaccine is given with a needle that has been dipped into the vaccine solution. The needle pricks the skin on your upper arm and leaves a droplet of the vaccine when it is removed. Pricking is done a number of times over a few seconds. This causes a sore spot and small blood droplets to form.

  • Within 5 days, a small bump forms on the area where the vaccine was given.
  • Within 10 days, the bump becomes filled with fluid and pus, and reaches its biggest size.
  • Within 21 days, the bump dries up and forms a scab. The scab then falls off after 3 to 4 weeks and leaves a scar.
  • You may have any of the following reactions after you get the vaccine:
    • Pain, itching, and inflammation around the vaccine area
    • Swollen lymph glands in your armpits
    • Fever

What should I do after I get the smallpox vaccine?

The virus can be spread before the scab falls off. Contact with the vaccinated area may easily spread the virus to other parts of your body. You may also spread the virus to other people through direct contact. The following may help prevent the spread of the virus:

  • Place a bandage over the vaccinated area. Wear a shirt with sleeves long enough to cover the vaccinated area.
  • Females should prevent pregnancy until a healthcare provider says pregnancy is okay.
  • Do not scratch or touch the vaccinated area on your arm.
  • Do not towel dry the area where the vaccine was given. Cover the area with a waterproof bandage when you bathe.
  • Do not donate blood, use a hot tub, swim, handle a baby, breastfeed, or get a TB skin test. Wait at least 30 days or until your healthcare provider says these are okay.
  • Wash clothes and bedding with water and a germ-killing solution.
  • Wash your hands with soap and water right away if you touch the vaccinated area.

What are the risks of the smallpox vaccine?

The area where the vaccine was given may be red, tender, or swollen. You may get a fever, mild rash, or swollen glands in your armpits. You can spread the virus in the vaccine to other people by accident. The area where the vaccine was given may get infected. The infection may spread to your eyes, heart, or brain. This can cause long-term damage. You may have an allergic reaction to the vaccine. This can be life-threatening.

Call your local emergency number (911 in the US) for any of the following:

  • Your mouth and throat are swollen.
  • You are wheezing or have trouble breathing.
  • You have chest pain or your heart is beating faster than normal for you.
  • You feel like you are going to faint.

When should I seek immediate care?

  • Your face is red or swollen.
  • You have hives that spread over your body.
  • You feel weak or dizzy.

When should I call my doctor?

  • You have a fever and a headache.
  • You have swollen lymph glands in your armpits.
  • You think the virus has spread to another part of your body.
  • Your wound from the vaccine gets larger or does not heal.
  • You have questions or concerns about the smallpox vaccine.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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