What are they used for?
Health care providers can usually diagnose chickenpox or shingles with a visual examination. Tests are sometimes ordered to check for immunity to the varicella zoster virus (VZV). You have immunity if you've had chickenpox before or have had the chickenpox vaccine. If you have immunity it means you can't get chickenpox, but you can still get shingles later in life.
Tests may be done on people who don't have or are unsure about immunity and are at higher risk of complications from VZV. These include:
Pregnant women
Newborns, if the mother is infected
Teen and adults with symptoms of chickenpox
People with HIV/AIDS or another condition that weakens the immune system
