How does oral herpes affect the body?

Oral herpes, or cold sores, is the result of an infection by the herpes simplex virus type 1. The virus is highly contagious, and it passes from person to person through physical contact. The virus causes an outbreak of small red sores on the skin, and even after the sores go away, the virus remains in the body. People may experience additional outbreaks of the virus from time to time.