I was born in ‘61, my smallpox vax was placed on the inside of my upper arm. It’s there but very faint.

Mine went away sometime between the ages of 16ish and now. I remember having a scar, I remember where it was and what it looked like, but I can’t find it anymore. I was told it was the smallpox vaccine, which my year was the last required to go to kinder in the state we lived in

Your fam members more likely have a TB (BCG) vaccine scar. From a quick google search, standard procedure in Qatar is to inject the upper arm, however it could be a bit away from the original site (proportionally) bc you grow. Some people may not form a scar with the BCG vaccine.

Neither do I - in my generation the only vaccine that left a scar was the BCG one. In those days they used to do a pre-test to see if there is a reaction (which suggests you already have antibodies), if there is you won’t be given the actual vaccine.