Varicella-Zoster Virus Antibody

Does this test have other names?

Serum varicella immunoglobulin G antibody level, chickenpox antibody test

What is this test?

This test looks for antibodies in your blood that your body makes against the varicella-zoster virus.

The varicella-zoster virus is very contagious. It can cause two health problems: chickenpox and shingles. When you become infected with the virus for the first time, it causes chickenpox. After having chickenpox, most people become immune to the virus for the rest of their life. They can't get chickenpox again.

But after the first illness, the virus becomes dormant and "hides" in nerves in your body. Later in your life (most common), the virus can become active again. It causes a painful rash called shingles (herpes zoster).

Why do you need this test?

You may need this test if your doctor needs to find out whether you are likely to get a varicella infection. This information can help health care workers who may work with patients who have the virus.

This test can also help your doctor find out whether you have chickenpox if the diagnosis isn't clear. Symptoms of chickenpox include:

• Fever.

• Headache.

• Sore throat.

• Distinctive rash a day or two after other symptoms begin.

The rash can last up to 2 weeks. The virus can be spread by touching the fluid of the skin lesions until all the lesions have crusted over.

What other tests might you have along with this test?

You aren't likely to need any other tests.

What do your test results mean?

Test results may vary depending on your age, sex, health history, and other things. Your test results may be different depending on the lab used. Ask your doctor what your test results mean for you.

If testing is done to see if you are at risk of developing an infection and it finds varicella-related immunoglobulin G (IgG) antibodies in your blood, it means you are immune. You have had a chickenpox infection or have been immunized successfully.

If your doctor suspects that you have chickenpox, your IgG levels can mean you have an infection if they rise over several weeks. In these cases, this test is usually needed only if your doctor is unsure about the diagnosis after examining you.

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 your test results?

Having a history of chickenpox or vaccine against the disease can affect your results.

How do you get ready for this test?

You don't need to prepare for this test. Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.