When having intercourse with a high risk sexual partner, how to prevent herpes simplex virus type 2?

Unless the: Person is taking medication to suppress it - you are at risk because the virus can shed even when there are no active lesions. A condom only provides coverage on the areas that it actually covers.

Preventing Herpes: There is no 100% solution here, unfortunately. The infected partner in a couple can be put on medication to suppress the viral shedding, but this protects against infection only up to 50%. If the infected partner is male and the infection is on the penis then condoms are very effective at preventing contagion. Herpes is transmitted skin to skin and can be caught even without an active sore.