Earlier quoted context omitted.
Why are you allowed to dictate how others raise their children? They don’t get a say in your kids diet or religion or choice of sport.
They do have plenty of influence over the environment your child lives in. Vaccination for public school entry would be a good example.
If Timmy is on Instagram, John’s health isn’t at risk. If Timmy comes to school with measles, John’s health is at risk, and vaccination has been shown to reduce the risk to both Timmy and John.