Can you quantify this? Perhaps a percentage?
I am sure the official version is that is “very rare”—under 1%.
That is very little comfort to folks who have gotten the side effect.
Shingles is caused by the same virus that gives you chickenpox. If you once had chickenpox you will still have the virus living dormant in your nervous system.
Anything that stresses your immune system could increase the chance of the dormant virus erupting as shingles. It’s not a specifically covid vax issue but the usual suspects would like you to think that it is.