Chickenpox is caused by the varicella virus or herpes zoster. Once infected with chickenpox, a susceptible individual can carry the virus in the para-spinal and other nerve ganglia for life. The virus can re-emerge at multiple times and at any point in later life along the sensory nerves of those ganglia erupting in patches of painful, clear vesicles, a condition called shingles. Vaccination usually results in immunity to chickenpox and precludes the subsequent occurrences of shingles. The virus can cause primary chickenpox in utero if susceptible mothers contract it.
chickenpox, shingles, herpes zoster