Hadn’t expected to see this; although it is a valid and genuine warning for younger people who are now in their teens/20s.
Before then there wasn’t as much (now discredited) paranoia about childhood vaccinations; TBH when I was a small child there seemed to be even more vaccinations (you would have to go with your parents to random government building near the main hospital site or it was done in the sickbay of school, often there were scary posters on the walls warning about all the diseases you could get if you didn’t have these jabs.). I think MMR had only just been invented when I was the required age and my local NHS region still gave separate injections!
I had to have some others on top of those before my parents visited Malaysia in the late 1970s – presumably they all did some good as I am still alive and in reasonable health for their age (this also put me off ever injecting drugs for enjoyment).
But if you didn’t have these vaccinations as a child and are going to any large gathering of people it is best to get them sorted out first, measles is nasty and contagious (it used to kill many people in the last century!)