Oh yes totally understand what you mean/meant

Personally, in so far as a belief in herd immunity, I think it is a very common misconception. The only true time herd immunity can exist ime is when you have a populationwho have been naturally exposed and/or infected with the natural virus and have overcome it, developed their antibodies naturally, and are therefor immune.
The notion of "reduced" risk is negligiable really - and this small percentage reduction when weighed against the ACTUAL infection risk rates, the ACTUAL serious injury/death from ACTUAL infection rates, and the risk of serious injury/death/toxicity from the vaccine itself, is totally negated.
The opportunity cost of vaccinating is so far and away greater than that of not vaccinating, even taking into consideration any reduced risk of infection.


ETA:
I should also add the caveat that I do not believe that naturally immunity is 100% 100% of the time either - I had chicken pox 4 times as a child/teen in varying degrees of severity.