I remember noticing a small scar on my mother’s upper arm when I was a child. It had a ring of tiny indents surrounding a slightly larger mark.
I don’t know why it caught my attention, but it did. Like most childhood curiosities, though, I eventually forgot about it.
Of course, the scar didn’t disappear—it was always there—but I stopped thinking about what had caused it. Maybe I asked my mother once, and maybe she explained. If she did, I don’t remember.
Then, years later, I helped an elderly woman off a train one summer. I happened to see the same scar, in the exact same spot as my mother’s. It immediately brought back my old curiosity, but with the train about to leave, I couldn’t ask her about it.
So, I called my mother. She told me she had actually explained it to me before—more than once, in fact—but I had never paid enough attention to remember. Her scar, like so many others of her generation, was from the smallpox vaccine.
Smallpox was a dangerous infectious disease that once spread widely among humans. It caused a severe rash, high fever, and in the 20th century alone, it killed about 3 out of every 10 people who caught it. Many who survived were left with scars.
The vaccine for smallpox was so effective that the disease was declared eliminated in the U.S. in 1952. By 1972, the vaccine was no longer needed as part of routine immunizations.
Before then, though, all children received the smallpox vaccine, which left a distinctive mark on their arms. In a way, it was like an early version of a vaccine passport—a visible sign that they had been immunized.
So, what caused the scar? Unlike modern vaccines, which use a single needle, the smallpox vaccine was given using a two-pronged needle that punctured the skin multiple times.
This method caused small blisters to form. Over time, these blisters scabbed over, eventually leaving behind the permanent scar.
And that’s the story behind my mother’s small but noticeable mark—one shared by many from her generation.