Does this test have other names?

Vaccine response test

What is this test?

This test looks for tetanus antibodies 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 painful muscle spasms, and trouble opening the mouth or swallowing. It also causes seizures and rigid muscles.

If you've 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 should receive a booster vaccine. The test will be repeated after at least a month. Several versions of the tetanus vaccine are available. The vaccine is recommended as a series in childhood. A booster vaccine is recommended every 10 years for teens and adults.

If you've never had a tetanus vaccine or been exposed to tetanus, you'll get vaccinated. You may return later to have your tetanus antibody levels checked to make sure the vaccine is working.

Why do I need this test?

You may need this test if your doctor wants to make sure your immune system has made enough antibodies to protect you against tetanus. Or you may need it to see if you have a problem that prevents your immune system from working correctly. This test can help diagnose:

• Severe combined immunodeficiency.

• Common variable immunodeficiency.

• Antibody deficiencies.

• Immunoglobulin deficiencies.

• Spleen problems.

• HIV infection.

You may also have this test if you:

• Get unusual infections.

• Need antibiotics more often than usual.

• Have infections in your sinuses, ears, or digestive tract that keep coming back.

What other tests might I have along with this test?

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

What do my test results mean?

Test results may vary depending on your age, gender, and health history. Your test results may also vary depending on the lab used. They may not mean you have a problem. Ask your doctor what your test results mean for you.

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 vaccine.

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Does this test pose any risks?

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

What might affect my test results?

Getting gamma globulin treatment in the 8 months before the test or immune globulin in the 5 months before the test will affect your results.

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

How do I get ready for this test?

Tell your doctor if you have cancer, are taking immune-suppressing medicine, or have received gamma globulin or immune globulin in recent months. 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 illegal drugs you may use.