Herpes zoster is one of the most common infections among elderly people all over the world. Based on the previous study, the overall incidence rate of herpes zoster was 4.47 per 1000person-years, where that was 12.78 per 1000person-years in high risk group in the U.S. [1]. The risk factors for herpes zoster were well-evaluated in previous studies. Aging [2,3], immune-compromised condition, including having malignancies [4,5], collagen diseases, diabetes [4], inflammatory bowel diseases (IBD) [4,6], and chronic obstructive pulmonary disease (COPD) [4] were considered as risk factors.
