Should children be vaccinated, yes, should it be required, no.
The parent may prefer alternative medicine or simply object on other grounds, and I say let them choose. However, the link to autism is total bullshit.
In the US, pediatric vaccinations are not mandatory, but the methods used to get parents to vaccinate their children are nothing short of extortion.
If you don't vaccinate your child, they cannot go to school.
Furthermore, if you refuse to vaccinate your child, more than a few jurisdictions will take you to court in order to relieve you of custody.