Originally Posted by JanMM

Correct that shingles is not a herd immunity thing - herd immunity only applies to contagious illnesses.
Perhaps someday if, because of childhood immunization, chickpox becomes uncommon, then so too will shingles. The only folks who are at risk of shingles are those who have had chickenpox. Which includes almost all of us here.
Correction: Shingles is a low level herd immunity thing because someone who has not had chickenpox and who has not been vaccinated against it (chickenpox) can catch it if exposed to an open shingles lesion. Not aware that happens very often.