Tetanus Antibody

Does this test have other names?

Vaccine responsiveness test

What is this test?

This test looks for tetanus antibody in your blood.

Tetanus is a serious disease caused by the toxin from Clostridium tetani bacteria. The toxin makes its way into the nervous system and causes muscle spasms and rigid muscles.

If you have been vaccinated for tetanus in the past, this test should show that you have enough antibodies against the disease. If your levels are too low, you will be revaccinated, and the test will be repeated after at least a month.

If you've never received a tetanus vaccination or you've been exposed to tetanus, you'll get vaccinated and return at later to have your tetanus antibody levels checked.

Why do I need this test?

You may need this test to make sure your immune system can protect you against tetanus or to see if you have a problem that prevents your immune system from working properly. This test can help diagnose:

  • Severe combined immunodeficiency, or SCID

  • Common variable immunodeficiency, or CVID

  • Antibody deficiencies

  • Immunoglobulin deficiencies

  • Spleen problems

  • HIV infection

You may also have this test if you get unusual infections, need antibiotics more frequently than usual, or have recurrent infections in your sinuses, ears, or digestive tract.

What other tests might I have along with this test?

Your doctor may also order tests to check your immune system's response to diphtheria vaccination or Streptococcus pneumoniae vaccination.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.

Results are given in international units per milliliter (IU/mL). Normal results are usually greater than 0.1 IU/mL. If the test shows your levels are at least that high, it means your immune system had a normal response to the tetanus vaccination.

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

Tetanus vaccinations, which are combined with vaccinations against diphtheria and sometimes pertussis, may cause these side effects:

  • Pain, redness, and swelling at the injection site

  • Fever or headache

  • Fatigue

  • Stomach upset

  • Allergic reactions

What might affect my test results?

Receiving gammaglobulin treatment in the eight months before the test or immune globulin in the five months before the test will affect your results.

Having cancer, receiving chemotherapy, or taking certain medications that suppress the immune system can also affect your results.

How do I get ready for this test?

Tell your health care provider if you have cancer, are taking immune-suppressing medication, or have received gammaglobulin or immune globulin in recent months. In addition, be sure your doctor knows about all other medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.