I never got a scar. When my Hubby was drafted they gave him another vaccination, since he didn't have the scar. They thought it didn't "take".
My little hometown was progressive and gave us our smallpox vaccinations on the inside of the arm, instead of leaving that scar on the outside for the world to see.
I can still see mine - *hanging down there*, lol. *thwapping the geezerette flab*