yeah, you get an immunity after getting CP but it’s not totally gone as CP goes dormant somewhere in your spine.
if your immune system gets compromised, old or stressed the virus can reactivate and flare up again. You do recover as the immune system responds but according to my bro its painful (left torso, but in a small area...Dr. confirmed).
I got shingles at age 35. Dr said I was youngest he had seen. My dad had it same time. We had visited my mom in hospital later found out her roommate had CP. I had CP in 2nd grade. Shingles on my torso very painful 2 weeks. I wore no bra and wore very soft large cotton short. Ouch!