They were never compulsory in the UK. But most people were a lot more pragmatic when you personally knew kids who died or were seriously ill as a result of things like Diptheria, Tetanus, Polio, Whooping Cough or Measles/etc.
I had my measles vaccination in 1979, Rubella in 1983/4. And I got myself a booster of everything I could aged 16 along with a later DTP aged about 30 when the ungrateful bastarding Best Cat in the World took a chunk out of my thumb as I was saving her life.
DP can only remember having a lump of sugar, which meant the DTP, and I know his father is a twat doesn't believe in vaccination, so it's likely that he never had MMR and hasn't had any boosters or later vaccinations. He doesn't remember ever being ill, but he did grow up in the arse end of nowhere, so he probably benefitted from herd immunity.
As he's already gone against his father's views (not that the stupid git knows) in having flu vaccinations for my protection/benefit, because he's seen how ill I was with influenza when we first started dating (bad timing - the vaccine wasn't at the GPs for another 3 weeks), he's going to find out if he can have all the other ones now.
I think having them as adults makes perfect sense - not all of us would have been vaccinated, record keeping was less of a thing when it was all done on paper/notes can be lost over thirty-odd years, and when people can't be relied upon to get their children vaccinated, making sure that those of us in that 'not quite so rigorous age of recordkeeping' are vaccinated is another way of protecting the immunocompromised, the allergic and the too young.