> Isn’t it sort of unethical to force parents to inject their child with something they think is dangerous?

Is it unethical to say parents should feed their kids if they believe food to be dangerous? Is it unethical to stop them from giving their kids bleach if they believe it to be a cure?

The answer is that as a society we have limits around what a parent can or cannot do for the sake of the overall well-being of their children. If a parent refuses to vaccinate their child without a very good reason why (such as other exacerbating health issues or allergic reactions), it should be treated as child abuse. Because it is.