Ping
I never got chicken pox as a kid, even though I was exposed to friends and family with it. I thought maybe I was one of the fortunate naturally immune. Wrong, I finally got them from my young son when I was 36. It was a horrible experience.
We need to see the age at which the vaccinated children are still getting the pox. That makes all the difference. This is a mild(er) disease in elementary age. Even only 80% of the disease in the older years (teen and adult) is far worse.