this should be higher up in the article, because I personally see way too much uncertainty out in the wild and online:
Getting another MMR shot is harmless if there are concerns about waning immunity, the CDC says.
even the most dogshit insurance covers "scheduled" immunizations like the MMR 100% and many/most public health departments will cover the cost from a doc-in-a-box or a pharmacy, though some of the crank controlled counties will be forbidden from promoting it to people via outreach unless they specifically ask.
so if you're even slightly unsure, go get stuck today. its a mosquito bite. taking off the band-aid 2 hours later hurts more.
this shit is going to continue to expand for the foreseeable future.