Varicella zoster virus or varicella-zoster virus (VZV) belongs to the family of Herpesviridae. VZV also known as chickenpox virus, varicella virus, zoster virus, and human herpesvirus type 3 (HHV-3). It is one of the eight herpesviruses known to infect humans. VZV multiplies in the lungs and causes a wide variety of symptoms. It causes chickenpox (varicella), a disease most commonly affecting children, teens, and young adults, and herpes zoster (shingles) in older adults; shingles is rare in children. After many years of recovery from the chickenpox, VZV can be re-activated and performed as herpes zoster.