Differences Between Hsv1 and Hsv2 The main differences between HSV-1 and HSV-2 are their typical location and frequency of outbreaks. Both are lifelong viruses that cause sores and are spread by skin-to-skin contact. **HSV-1** is most commonly associated with **oral herpes** (cold sores around the mouth), but it can also cause genital herpes through oral sex. It often causes a milder initial outbreak and may recur less frequently in the genital area. **HSV-2** is almost exclusively the cause of