VZV infection: epidemiology and prevention

Varicella is an infectious disease caused by a virus (VZV), identified almost a century ago, belonging to herpesvirus family. The disease mostly affects younger age classes. Considered a mild disease, in some cases, especially in immunocompromised subjects, varicella can be more severe, even fatal. The clinical course in adults is longer and more severe in respect to childhood disease. VZV infection in susceptible pregnant woman, even if rare, can be related to disabling syndrome both in woman and offspring, such as congenital and neonatal varicella. During primary infection, VZV has the ability to become latent in the sensory-nerve ganglia and to cause, many years later, the reactivated form, herpes zoster. The epidemiological relevance of varicella, the availability of a live, attenuated, safe and effective vaccine, have prompted an ample international debate on the opportunity of extensive infant varicella vaccination. Recently, the capacity of a new high-potency, live, attenuated varicella zoster vaccine to reduce the morbidity associated to zoster and its complications has been demonstrated.