I also have a healthy immune system - waited 6 months between shots, so probably that did not affect. I don't think anyone is aware of this as a possible side effect of the vaccination. Certainly dermatologists don't seem to be aware. The case of shingles I got after the last shot was pretty mild. Had never had shingles before. GD started almost immediately afterwards. But I had had itching between my shoulder blades for several years - worse at night, but never a rash. My husband was slathering cream on my back every night because I thought itching was caused by dry skin. Then after shingles resolved, my husband started seeing the rash which then covered my entire torso, front and back, wherever there had been previous sun damage. How these are all linked is an interesting mystery.