Grandmothers story

I do not have an autistic child, but I have friends who are dealing with this issue. I love their children like my own.
My Mother says that back in the old days when a child was vaccinated, they would watch their diet very closely for at least 72 hours before and after.
My mother is not a doctor, nor my grandmother. But my mother says she was told not to give children acidic food for several days!