Varicella – Zoster Virus Varicella zoster virus is a common virus which causes highly contagious disease of chickenpox. It mainly infects children, teens and young adults. Varicella zoster virus, also known as human alphaherpesvirus -3, is one of the 9 herpes viruses which mainly infects only. This virus develops life-long latency by residing in basal ganglia, cranial roots and autonomic ganglia. It transmits by respiratory droplets and direct touch.