 This study is being done to evaluate the zoster vaccine response in the nursing home elderly 80 years or older. As the immune system ages, the response to vaccines is not always as strong as in younger people. Previous zoster vaccine studies have excluded nursing home residents so the vaccine effect in this population is not known. Furthermore, the immune and genetic reasons as to why the vaccine works well in some people but not in others are also unknown. The goal of this study is to evaluate why some immune systems respond well to the vaccine and why others do not. 