I consulted with another herpes expert about your question and they agree that we just don’t know if people with immune problems are more likely to acquire herpes or not.
I don’t know why WebMD would say that people with herpes have back pain or any other site. As I mentioned, sometimes people who have herpes do have neuralgia down the back of the leg prior to, during or after an outbreak but generalize low back pain does not fit with a herpes diagnosis that I am aware of.
Terri