You can't make vaccinations "mandatory", but you can make them the basic benchmark for participation in society.
In Ontario and New Brunswick, proof of vaccination is already required for children to attend school. But parents can get an exemption in both provinces for medical, religious or philosophical reasons, as long as they fill out a form.
This right here is the problem. Kids should need vaccinations to go to school or to receive government benefits of any kind, unless there is a firm medical reason that precludes them. Religious or philosophical excuses are not sufficient. If you don't want to get vaccinated then you don't want to participate in modern society.