Cold sore triggers vary from person to person, but HSV is an opportunistic infection. That means it rears its ugly head when, for whatever reason, your immune system is too weak to Liposomal Glutathione Highly Bioavailable Glutathione Designs for Health AU Manipulation of Oxidative Stress Responses by Non Thermal Plasma to Treat Herpes Simplex Virus Type 1 Infection and Disease Researchers Now Understand How a New Class of Antivirals Works Harvard Medical School