People in lots of Asia are required to get the smallpox vaccine. Here where I am they receive it in their upper arm. It leaves an ugly scar, round about the size of a dime or penny. Usually it's an indention ("pock mark") but sometimes it kindof is a sticking-out growth and red. In any case, it is NOT pretty on girls wearing short sleeves or sleeveless tops.
I understand that in America we don't routinely take that one (thank God). I've always thought how ghastly it would be to have such an ugly scar on my arm! They should give that one in the butt (if at all).