What is Chickenpox and Shingles?

Varicella-zoster virus (VZV), a human herpesvirus, causes chickenpox (varicella) on primary infection and can reactivate years later from sensory ganglia to cause shingles (herpes zoster).

VZV is highly contagious via airborne droplets and direct contact with vesicle fluid. Serology (VZV IgG/IgM) is widely used to confirm immunity, diagnose acute infection and support vaccine studies.

Transmission & symptoms

VZV spreads through airborne respiratory droplets and direct contact with the fluid of chickenpox or shingles blisters. Primary infection causes varicella (chickenpox) — fever and an itchy vesicular rash — after which the virus becomes latent in sensory (dorsal-root) ganglia and can reactivate decades later as herpes zoster (shingles), often with post-herpetic neuralgia.

Diagnosis & serology

VZV infection and immunity are assessed serologically. Anti-VZV IgM indicates recent or active infection, while anti-VZV IgG confirms past exposure or vaccine-induced immunity — the standard read-out for immune-status screening in healthcare workers and pregnancy. ELISA against VZV glycoprotein antigens is the routine format.

Research applications

Research tools support studies of VZV latency and reactivation, vaccine immunogenicity (varicella and recombinant zoster vaccines) and the host immune response, including interferon and inflammatory-cytokine profiling during reactivation.