Herpes simplex virus type 2 (HSV-2) infects the genital mucosa and establishes a lifelong infection. As HSV-2 is the most common cause of recurrent painful genital lesions, there is a great need for a vaccine to protect from infection and to reduce symptoms. Simplexia uses a new strategy to develop a sub-unit vaccine. Based on the failure of vaccine trials in humans, we suggest that a vaccine should be based on the HSV-2 type-specific glycoprotein G-2 (gG-2). The vaccine induces complete protection from disease after genital HSV-2 infection in mice. The primary goal of the project is to conduct clinical phase I / II studies in humans.