I have a clear memory of noticing a distinct scar on my mother’s arm when I was a child ... scar had come courtesy of the famous smallpox vaccine. Smallpox is a viral, infectious disease ...

Depending on when and where you were born, you might have a particular scar on your arm that everyone else around you also has. This, as many of you probably already know, is the smallpox vaccine.

I still have a small round scar on my upper arm from the smallpox vaccine — a shot that’s no longer given to children because vaccines, along with assiduous containment of outbreaks ...