WHAT IS VARICELLA ZOSTER?
Varicella zoster is a virus. It causes chickenpox, also called varicella and shingles, called herpes zoster. After the chickenpox runs its course, the virus retreats to nerve tissues near your spinal cord and brain, where it hides out.
Varicella has an incubation period of 10-21 days. The infection spreads in a similar way to colds and flu.