I don’t think the chicken pox vaccine is solely related to shingles, because mny older people have gotten shingles, and they had chicken pox before the vaccine came out in the US in 1995.
Most people who get shingles actually also had chicken pox, has nothing to do with the vaccine!!
Chix pox immunity degrades. In the old days before the day care vaccine was used all the children got chix pox and most adults were re-immunized each time they came in contact with them. Not anymore.
As a matter of fact as a child the only adult I recall who had shingles was a woman who lived in a boarding house and had no family.