My child received her C.P.booster shot 5 weeks ago. This time she got a mild case of C.P. Two weeks later I got shingles. Why? My older children had full blown C.P. I had C.P. My immunity system is NOT compromised. I believe the vaccines are being made with a new strain of the C.P. family, which makes no sense to me at all. This very well could explain the children's developing shingles, andtheir reaction when exposed to traditional chicken pox, they have half an immunity so they react with shingles. A different strain is different.