I thought herpes lives your spinal cord?
Herpes simplex virus types 1 and 2 (the latter usually causing genital herpes, the former usually oral herpes, but often in either place) tend to reside in the sensory neurons, usually. Once it's there, it becomes latent (dormant) and stays there for life, without symptoms. Occasionally the mouth and genital symptoms do come back due to reactivation of the virus due to stress, immunosuppression, etc. These reactivations can be treated with topical antivirals, but they won't get rid of the latent herpes in your neurones.
It's in the severely immunocompromised that herpes simplex is a problem, as it can cause viral meningitis and, in severe cases, viral encephalopathy. These patients can be very ill indeed, and the virus is often cultured in the cerebrospinal fluid.
It's the same method for chickenpox virus, a member of the same family of viruses (human herpesvirus 3, a.k.a. Varicella-Zoster Virus) which becomes dormant in the dorsal root ganglion just outside the spinal cord. When they reactivate following (usually) immunosuppression or stress, it causes the symptoms and characteristic dermatomal "band" rash of shingles (as the virus tends to reactivate from the one specific sensory neuron and thus spread to where that specific nerve fibre starts on the skin).
You can't get shingles without having had chickenpox in the past at some point. Note that chickenpox in adults is very serious stuff, and can be seen seen in the immunocompromised where again both chickenpox and shingles can affect the central nervous system and make people very unwell. Chickenpox can also affect the pregnant and cause severe damage to the baby.
Herpes viruses: serious business.
