Chickenpox does not occur a second time, but the virus that causes chickenpox is called varicella-zoster virus, and it can cause a second infection, and even third and fourth infections. However, only the first of these infections is chickenpox, and the remaining second and subsequent infections are not called chickenpox, but rather shingles. The reason for this is that the body’s immune system does not recognize the virus in the first infection, so it causes a generalized infection with a rash on the head, face, neck, trunk and limbs. After this infection, the body’s immune system is able to maintain the relevant immune memory, so that a second infection does not cause a generalized infection. The second infection will only cause a localized infection with a localized rash called herpes zoster. This is because after the first infection, the body’s immune system is able to recognize the virus, and during the second infection it is not a foreign virus that invades the body, but rather the virus from the first infection is latent in the nerve root cells, and when the immune system is low it multiplies and becomes active again to cause a local infection. The local infection is confined to the area innervated by the nerve and does not spread to other areas.