New study sheds light on the causes of cold sores, herpes flare-upsHerpes simplex virus-1 (HSV-1) is one of the most common human pathogens in existence, present in approximately 40–90% of the population worldwide.Neurons infected with herpes simplex virus 1(photo credit: DR. FRED MURPHY/SYLVIA WHITFIELD/USCDCP/PIXNIO/COURTESY)
