There were before too but very rare, the uncertain with covid vaccines brought more people on that side
Here vaccinations are mandatory for kids, if you don't they can't go to kindergarten and you get a fine to pay, but the shool from 6 years on can't be banned is mandatory so even without vaccines they are allowed to go
I've done all vaccines to kid, they are safe and tested since ages, on the other side I did not vaccine him for covid, mrna has too much unknown stuff