I remember clearly the first time I noticed a distinct scar on my mother’s arm when I was a child, high up near her shoulder in an unusual pattern. It was a ring of small indents around a larger mark that immediately caught my eye.

At the time, I don’t really know why it held my fascination, but I remember staring at it and wondering what had caused such an odd-looking mark to appear on her skin. It was strangely intriguing to young me.

Over many years I forgot my childhood interest in that scar, though the scar itself never went away. It remained exactly where it always was, a quiet reminder of something my young mind once found curious.

I might have asked my mother about the scar when I was small, and she likely told me its origin. But if she did explain, my brain didn’t consider that information crucial enough to hold onto.

With the train about to depart, I didn’t have the chance to ask her about the scar’s origin. Instead, my curiosity brought back the long-forgotten memory, and I immediately called my mother for an explanation.

To my surprise, she told me she had explained the origin to me more than once when I was younger, even if I now couldn’t remember it. She said the scar came from her smallpox vaccination.

Smallpox was a viral infectious disease caused by the variola virus that once afflicted humans far and wide. Before eradication, it spread through populations, causing high fever, rashes, and deep skin lesions.

This deadly disease killed roughly three out of every ten infected victims in major outbreaks, often leaving survivors with disfiguring scars across their body and even blindness in some cases.

In fact, thanks to these efforts, smallpox was declared eradicated worldwide in 1980 following the last naturally occurring case in 1977.

Because smallpox no longer circulates in nature, routine vaccination of the general population ended in the United States in 1972.