Boomers have the mark! I don't remember getting it either. But I have the brand!
I have the Mark of the Vax,

. I vaguely remember it being done, probably between ages 6 and 8. Back when I was able to donate blood, there was a carelessly worded question among the screening questions, whether I had been vaccinated for smallpox. The purpose of the question was a relatively recent round of vaccinations, but because the question was non-specific I always answered "Yes" and had to explain to the (young) nurse/aid that more or less every Boomer had been vaccinated as a child.
I distinctly remember getting a polio vaccine on a cube of sugar while at school in the third grade.
Likewise, in the early 60s. I was single-digit-aged, and the distribution was at the local high school. IIRC, I went with my family on a Sunday after church. Also IIRC, a drop of pinkish liquid was put on the sugar cube.