About the Varicella Titer
Purpose of the test
The varicella titer shows whether you have protective immunity against VZV. That immunity comes from either a past chickenpox infection or vaccination. Providers order it when immunity status is unknown and documentation is needed for employment, school enrollment, pregnancy planning, or clinical care.
VZV causes two distinct diseases. Chickenpox (varicella) happens on first exposure. The virus doesn’t leave your body after that. It stays dormant in nerve tissue and can reactivate later as shingles (herpes zoster), a painful rash that sometimes leads to lasting nerve pain. The CDC’s chickenpox overview describes both diseases and their complications.
Chickenpox hits harder in adults, pregnant people, newborns, and those with weakened immune systems. Some people, including those who are immunocompromised or pregnant, can’t receive the live varicella vaccine. Knowing the immunity status of people around them matters for their safety. VZV infection during pregnancy can cause two serious conditions:
- Congenital varicella syndrome: occurs when a pregnant person contracts varicella for the first time during the first half of pregnancy and passes the virus to the fetus, causing skin lesions, limb abnormalities, and neurological or eye defects.
- Neonatal varicella: occurs when a newborn is exposed without maternal immunity, which can lead to severe, sometimes life-threatening illness.
Vaccine-induced immunity can fade over time. A study published in the New England Journal of Medicine found that people vaccinated against varicella had detectable antibodies for at least 10 to 20 years after vaccination, though the full duration of protection is not known. The titer tells you your current immune status, not just whether you were vaccinated years ago.
This test doesn’t diagnose active chickenpox or shingles. It can’t tell you whether your immunity came from natural infection or vaccination, either. If you have an active rash or symptoms, you’ll need a different test. A polymerase chain reaction (PCR) test, performed on fluid or scabs from lesions, is the most sensitive method and usually returns results within about a day. A direct fluorescent antibody (DFA) test or viral culture can also detect an active VZV infection but is less sensitive than PCR.
What does the varicella titer measure?
The varicella titer measures one marker from a single blood sample processed at a Clinical Laboratory Improvement Amendments (CLIA)-certified lab.
VZV IgG antibody: IgG antibodies to VZV show up in your blood after your immune system responds to a chickenpox infection or a vaccination and serve as an indication of immunity, but not particularly useful in diagnosing an active infection. They stick around long-term as a marker of immunity. Labs report this result in one of two formats: qualitative (positive, negative, or equivocal) or quantitative (a numeric IgG concentration in IU/mL or mIU/mL, or ratio/index with a reference range). Most consumer-ordered and compliance tests use the qualitative format. A quantitative result helps when a borderline finding needs more context or when a provider wants to track antibody levels over time. Reference ranges vary by lab and assay, so the cutoffs on your report are the ones that matter. Talk to your provider about any unexpected result. The National Library of Medicine’s chickenpox page has background on VZV and how the immune system responds.
The test measures IgG antibodies only. IgM antibodies, which may point to a recent or active infection, need a separate test. Some labs offer a combined IgG/IgM panel, but the standard varicella titer is IgG only.
When should I get a varicella titer?
Consider testing if any of these apply:
- A job, school, or health care facility requires proof of VZV immunity
- Your vaccination record is incomplete, lost, or unavailable
- You aren’t sure whether you had chickenpox or got the vaccine
- You’re pregnant or planning pregnancy with unknown immunity status
- You have a weakened immune system and concern about VZV exposure
- You were recently exposed to someone with chickenpox or shingles
- You’re traveling to a region with lower varicella vaccination rates
For routine screening, clinical guidelines recommend VZV immunity checks for:
- Health care and childcare workers at the start of employment or training, per CDC guidance on immunization of health care personnel
- Pregnant people at the first prenatal visit, per the American College of Obstetricians and Gynecologists (ACOG)
- People starting immunosuppressive therapy or organ transplant workups, before treatment begins
How It Works
How to get tested
Ask your provider for a varicella titer. Most providers order it through CLIA-certified labs such as LabCorp and Quest Diagnostics for in-lab blood draws. Results come back through the ordering provider’s patient portal or office.
Consumer-initiated varicella titer tests are available through LabCorp OnDemand and Quest Health without a provider visit. An independent health care provider reviews and approves the order. If you need the result for compliance documentation, confirm with the requesting institution whether consumer-ordered results are accepted. Requirements vary by employer and school.
Before the test
No fasting required. Eat and drink normally. The test measures antibody levels, not metabolic markers like glucose or cholesterol. Tell your provider about any immunosuppressive medications, chemotherapy, or recent treatments that affect immune function. These can lower antibody levels and change how your result is read.
If you were recently vaccinated against varicella, wait at least four to eight weeks before testing. Testing too soon can produce a false negative.
Wear a short-sleeved shirt or sleeves that roll up easily. Drink water beforehand. Good hydration makes veins easier to find.
During the test
A phlebotomist cleans a small area on the inside of your arm with an antiseptic wipe. A needle goes into a vein, usually in the crook of your elbow, and draws a small blood sample into a tube. The whole thing takes about one to two minutes. A bandage or cotton ball covers the site afterward.
Expect a brief pinch. Most people find it mild. Some feel lightheaded during or right after the draw. Tell the technician if that happens. They’ll have you sit or lie down until it passes.
No urine, swab, or physical exam is involved. There’s no monitoring period afterward.
Keep the bandage on for at least 15 minutes to ensure bleeding has stopped. Avoid heavy lifting with that arm for a few hours. Call your provider if you notice lasting pain, major bruising, swelling, or signs of infection at the site.
After the test
Results are typically ready within one to three business days after the lab receives your sample, though timing can vary by lab. For provider-ordered tests, results come through the patient portal or office. For consumer-ordered tests, results appear in your secure online account.
If you need results for compliance documentation, build in extra time. Institutions often take additional days to process what you submit.
What do my results mean?
Most labs report a qualitative result: reactive (immune) or non-reactive (not immune). Some report a numeric IgG concentration with a reference range. Both formats appear on varicella titer reports.
| Result | What it means | Quantitative IgG level (example) |
| Positive / Reactive | Immune | ≥ 1.10 index value or above lab cutoff |
| Equivocal / Indeterminate | Borderline; repeat testing recommended | 0.90–1.09 index value (varies by lab) |
| Negative / Non-reactive | Not immune | < 0.90 index value or below lab cutoff |
Cutoffs vary by lab and assay. The numbers on your report are the ones that apply.
A few things can affect your result. Immunosuppressive medications, chemotherapy, or immune conditions can lower antibody levels, producing a negative result in someone who may still have some immunity. Testing too soon after vaccination does the same. A positive result alongside active symptoms needs clinical context, because the test can’t separate past from current infection on its own.
If your results are positive (immune)
IgG antibodies to VZV were detected. Your immune system has responded to past infection or vaccination. Most people with a positive result have protective immunity against chickenpox.
A positive result doesn’t guarantee lifelong protection. Immunity varies based on individual factors, timing of vaccination, and antibody levels. If you have active chickenpox or shingles symptoms alongside a positive result, talk to your provider.
For compliance documentation, a positive result counts as proof of immunity for most employers, schools, and health care programs. Confirm specific requirements with the requesting institution.
If your results are negative (not immune)
No detectable IgG antibodies to VZV were found. Two situations are common. Either you’ve never had chickenpox and weren’t vaccinated (or vaccination was incomplete), or you were vaccinated but immunity has faded. As noted by CDC varicella vaccination guidance, vaccine-induced antibodies may persist for at least 10 to 20 years, though the full duration of protection is not known.
For most unvaccinated adults, a two-dose varicella vaccine series is recommended. If you were previously vaccinated and your titer is negative, a single booster dose is the usual next step.
Pregnant people can’t receive the live varicella vaccine. A negative result during pregnancy means close monitoring and VZV exposure precautions until after delivery before you can be vaccinated. If you’re immunocompromised, talk to your provider first. The live vaccine may not be safe depending on your condition.
If your results are equivocal
Antibody levels are borderline. They’re neither clearly positive nor clearly negative.
Equivocal results happen when antibody levels are low but detectable, when testing comes too soon after vaccination, or when the immune system is suppressed. Your provider will typically recommend repeat testing in four to six weeks or a booster dose. The decision depends on why you’re testing and your medical history.
For compliance documentation, an equivocal result won’t count as proof of immunity. The institution will guide next steps.
FAQs
Sources
CDC. Chickenpox (Varicella). 2024.
CDC. Varicella Vaccination: What Everyone Should Know. 2024.
ACOG. Immunization for Women: Varicella. American College of Obstetricians and Gynecologists.
MedlinePlus. Chickenpox (Varicella). National Library of Medicine.