Incidentally, mumps is something that is decreasing in prevalence because of coronavirus precautions. In normal times, 88% isn't quite enough for herd immunity to mumps and there are sporadic outbreaks. I (M35) got it last year even though I was vaccinated along with almost everyone from my age cohort and younger, and everyone significantly older is immune because they contracted it in childhood. But that outbreak which began in late 2018 went away very quickly in April-May 2020 [0]

[0] https://www.hpsc.ie/a-z/vaccinepreventable/mumps/