Regardless of where we end up with respect to vaccination of children for COVID-19, I hope we can all agree that the child's opinion is irrelevant, given that they are not equipped to make an informed decision.
Neither can we expect an average adult to be able to make an informed decision on a topic like this. But if he really wants it, and the shot is optional, why do you believe that should be irrelevant to my decision?
The child's opinion certainly isn't irrelevant, especially if they are a child with special needs who can find the process of getting a vaccine very traumatic.
