VZV-specific cell-mediated immunity, but not humoral immunity, correlates inversely with the incidence of herpes zoster and the severity of skin symptoms and zoster-associated pain: The SHEZ study

Onset of herpes zoster (HZ) is thought to be related to a decline in cell-mediated immunity (CMI). However, until recently, there have been no large-scale prospective studies on the relationship between varicella-zoster virus (VZV)-specific CMI and the onset and severity of HZ. The Japanese researchers conducted a cohort study on VZV immunity in a population living on an island cluster, Shozu County in Japan, and examined the people who developed HZ during a follow-up period of three years to clarify the relationship between the onset and severity of HZ and immunity. In this study, they focused on the relationship between cell-mediated and humoral immunity and the onset and severity of HZ. CMI was measured by VZV skin test, and humoral immunity was assessed with serological tests for VZV-specific antibodies. A total of 12,522 people over the age of 50 were enrolled in this study, and 401 registrants were diagnosed as HZ. VZV-specific CMI assessed by VZV skin test showed a significant inverse relationship with the incidence of HZ and the severity of skin lesions and acute and subacute pain, and with the occurrence of postherpetic neuralgia. In contrast, VZV-specific antibody titer was not associated with the incidence and severity of HZ. These results suggest that VZV-specific CMI, but not humoral immunity, plays a key role in controlling the onset of HZ, the severity of skin lesions, and zoster-associated pain.