Herpesvirus infections are widely spread throughout the world population. Herpes simplex virus (HSV) belongs to the α-herpesvirus subfamily. There are two main types of HSV, HSV-1 and HSV-2, which infect humans. HSV-2 mainly causes genital lesions, whereas HSV-1 is involved in both oral and genital infections. Glycoprotein D (gD) is a structural component of the herpes simplex virus type 1 (HSV-1) envelope which is essential for virus entry and fusion with host cells. gD plays an important role by binding to the host receptors such as herpes virus entry mediator (HVEM) and nectin-1, a member of the immunoglobulin (Ig)-like cell adhesion molecules.