An effective and safe live attenuated vaccine against varicella zoster virus was developed in Japan in the 1970s and has been in widespread use since the mid-1990s. In the United States, universal vaccination has brought about striking reductions in varicella incidence together with associated hospitalizations and mortality. However, it is clear that varicella will continue to occur even in highly immunized populations, owing to the ability of VZV to reactivate as zoster. In addressing this challenge, attention is currently focused on efforts to minimize the proportion of susceptible individuals by administering a second dose of vaccine to children. The potential of the newly licensed zoster vaccine to reduce viral circulation still further has yet to be evaluated.