What Are Causes of Shingles? Herpes zoster virus causes shingles. No one knows for sure what causes the chickenpox virus to become reactivated to cause shingles. What is the varicella-zoster virus and how does it cause shingles? How are chickenpox and shingles different? Who is at risk for shingles? How is shingles treated? Can shingles be prevented? What is postherpetic neuralgia? What are other complications of shingles? Can infection with VZV during pregnancy harm the baby? What research is being done? How can I learn about or participate in clinical research? Where can I find more information about research on shingles? Where can I get more information? Glossary. This second eruption of the chickenpox virus is called shingles or herpes-zoster.