Chickenpox immunity blood test in Chiswick

What the test measures

Chickenpox is caused by the varicella zoster virus, the same virus that can later reactivate as shingles. After an infection or a course of the chickenpox vaccine, your immune system makes IgG antibodies against the virus, and these usually stay in the blood for many years. This test looks for those IgG antibodies to show whether your body has met the virus before.

A positive IgG result generally means you are immune. It does not tell you when the infection happened, and it is not designed to confirm a chickenpox rash you have right now, which is usually recognised by its appearance. The price includes the blood sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a review of your result with an Omnia practitioner and a GP feedback report on request.

Who it is for

• You are planning a pregnancy and are not sure whether you had chickenpox as a child.
• You work, or are about to work, in healthcare, childcare or education and have been asked for evidence of immunity.
• You grew up in a country where chickenpox was less common in childhood and want to know your status.
• You are considering the chickenpox vaccine and would like to know whether you need it.
• Your GP or employer has asked you to confirm varicella immunity.

Understanding your result

Your report will show whether varicella IgG antibodies were detected, usually as positive, negative or equivocal, with the laboratory reference range. A positive result suggests past infection or vaccination and likely protection. A negative result suggests you may not be immune, and your practitioner can talk you through vaccination options with your GP or a travel clinic.

An equivocal result sits in a grey zone and may need repeating. Antibody levels after vaccination can be lower than after natural infection, so a weak result is a prompt for discussion, not a firm answer either way.

Preparing for your test

No fasting or special preparation is needed, and you can eat and drink normally. If you are pregnant and think you have been in contact with chickenpox or shingles, do not wait for a booked test: contact your GP or midwife promptly, as advice may be time-sensitive.

If you are preparing for pregnancy, our fertility blood tests look at hormones and wider health alongside this check. Take a look at every blood test and price in Chiswick.

Questions

How much is a chickenpox immunity test in Chiswick?

The chickenpox immunity (varicella) test costs £89. This covers your blood sample at our W4 clinic, laboratory analysis, a practitioner review of your result and a GP feedback report if you would like one.

Can this test tell me if I have chickenpox now?

It is not the right test for a current rash. IgG antibodies take time to develop, so early in an infection the result may still be negative. If you think you have chickenpox, speak to your GP or NHS 111, particularly if you are pregnant or have a weakened immune system.

I had the vaccine. Will it show up?

Vaccination usually produces IgG antibodies, so a positive result is common after two doses. Levels can be lower than after natural infection, and some laboratory methods may not pick them up, so your practitioner will read the result alongside your vaccination history.

What if my result is negative?

A negative result suggests you may not be protected. Your practitioner can explain your options, which may include discussing the chickenpox vaccine with your GP or a pharmacy that offers it.