Test Details: Varicella zoster virus tests detect either antibodies produced by the immune system in response to a VZV infection or detect the virus itself. Chickenpox and shingles are caused by an infection with the varicella zoster virus (VZV), a member of the herpes virus family. A positive IgG ELISA result indicates that a person has antibodies to VZV either from past varicella disease or vaccination. This test cannot distinguish whether the antibodies were from a past episode of varicella or vaccination.