This study will examine the structure of the receptor molecule for the herpes simplex virus (HSV) and determine if the receptor's structure is related to susceptibility to infection with the virus. There are two types of herpes virus-HSV-1 and HSV-2. HSV-1 commonly causes cold sores, and HSV-2 usually causes genital herpes. The herpes virus enters (infects) cells through protein molecules on the cell's surface. This study will explore possible differences between the structure of the HSV receptor molecule in different people to understand better how infection occurs. The study will also look at proteins on white blood cells (Fc receptors, cytokines and mannose binding protein) that may influence the risk of infection with HSV. Information from this study may lead to new treatments to prevent HSV infection.