Pathophysiology of Varicella Zoster Virus (VZV) VZV enters a human body by inhaling infected respiratory droplets expelled by coughing and sneezing or direct skin-to-skin contact. VZV observes incubation period of 10-12 days. After incubation, the virus becomes active and spreads to lymph nodes, lungs and liver. This process is called primary viremia. Soon the virus progresses towards skin while the immune system produces CD4+ and CD8+ T cells. Here begins secondary viremia. When the virus invades skin it produces small pus-containing vesicles. These are called chickenpox. Resolution may be followed by reactivation even after several years. The virus resides in basal ganglia and ganglions where it activates under neurological conditions, medicines, malnutrition, illness, aging and idiopathic decline in immunity.