Herpes simplex virus (HSV) is one of the most common human pathogens. Based on the antigenicity of HSVs, the viruses can be divided into HSV type 1 (HSV-1) and HSV type 2 (HSV-2); both types share a high degree of genetic homology.(1) HSV-1 is the most common cause of oral herpes, while HSV-2 is the most common cause of genital herpes, which is one of the most common sexually transmitted diseases (STDs).