How common is oral herpes?

Very common: Oral herpes is very common. It is believed that 50% to 80% of adults have the virus, although not everyone who has the virus will experience sores or symptoms.

Fairly common: Oral herpes is more common than one might think. It comes from the herpes simplex virus type 1 (genital is type 2). Most people are actually infected with the oral herpes virus in early childhood, but not everyone shows signs. Most common sign is the peri-oral lesion, more commonly referred to as a cold sore or fever blister.

Very common: As with any viral infection, there are multiple factors involved. Factors such as host immunity, method of transfer, and verulence of the virus, are examples.