Varicella zoster (chickenpox) IgG and IgM

Unsure whether you had chickenpox as a child? Antibody testing for varicella zoster virus (VZV) shows whether you are protected through previous infection or vaccination. The answer is especially important before pregnancy, after a pregnant woman has contact with an infected person, and before treatment that weakens immunity.

Who is this test for

• adults who do not know whether they have had chickenpox, before deciding on vaccination;
• women planning pregnancy;
• pregnant women immediately after contact with someone with chickenpox or shingles;
• healthcare workers, childcare workers and teachers;
• people before transplantation, chemotherapy or treatment with immunosuppressive medicines;
• people with an unusual blistering rash when a doctor wants confirmation.

If someone with chickenpox has difficulty breathing, a severe cough, confusion or a stiff neck, or if the disease occurs in a newborn, call emergency services immediately (194 or 112).

What the test reveals

The same virus causes two diseases. Chickenpox is the first infection, usually in childhood, with a blistering rash over the whole body. Afterwards, the virus remains dormant in nerves for life and may reactivate years later as shingles, a painful band of blisters on one side of the body. Adults, pregnant women and people with weakened immunity usually experience more severe chickenpox than children.

• VZV IgG shows whether you are protected against chickenpox and remains for life.
• VZV IgM is tested when a recent infection is suspected, but also occurs in shingles, so it does not distinguish these two diseases on its own.

The test and preparation

A venous blood sample is taken, which takes a few minutes. You do not need to fast or prepare specially. Tell us if you have been vaccinated against chickenpox, are pregnant or have recently received blood or immunoglobulins, because this affects interpretation.

What your results mean

• IgG positive: you are protected against chickenpox. Shingles may nevertheless occur later because the virus remains dormant in the body.
• IgG negative or borderline: protection is not confirmed. Your doctor may recommend two-dose vaccination, but not during pregnancy; pregnancy should be postponed for one month after vaccination. In vaccinated people, this test sometimes fails to detect antibodies, so negative IgG after two doses does not necessarily mean there is no protection.
• IgM positive: a recent infection or shingles is possible, but so is a false-positive result. Diagnosis is usually made by examination; if needed, the doctor arranges PCR testing from a blister.

The cut-offs are printed on the report. A doctor interprets the result alongside information about illness, vaccination and contact.

How to arrange testing

You can come for blood collection without an appointment or referral at one of our branches throughout Croatia (listed on the Contactpage). Prices for all tests and panels are listed in the price list. If you are planning pregnancy, alongside chickenpox you can also check protection against rubella.

Frequently asked questions

I am pregnant and have been in contact with chickenpox. What now?

Contact a doctor the same day, without waiting for symptoms. IgG testing shows whether you are protected. If not, the doctor assesses whether you need post-exposure protection, such as immunoglobulins or an antiviral medicine. This works only if given in time.

Is shingles the same as chickenpox?

They are caused by the same virus. Shingles is reactivation of the virus in someone who has had chickenpox. A person with shingles does not transmit shingles, but contact with the blisters can give chickenpox to someone who is not protected.

Can I get chickenpox twice?

This is rare. Previous infection usually provides lifelong protection, and if vaccinated people do develop the illness, it is usually mild.

Do I need testing before vaccination?

Not necessarily, because the vaccine is safe even for those who have already had the disease. For adults who do not remember having it, testing may avoid unnecessary vaccination because most have had chickenpox after all.