Many people of a certain age have a small, round, sunken scar on their upper left arm that often goes unnoticed or is mistaken for a simple birthmark.
However, this mark on the skin carries a story of great medical and social importance and represents one of the most significant milestones in the global fight against disease.
That distinctive scar comes from the smallpox vaccine, one of the most widespread and successful immunization campaigns in history. For several decades during the 20th century, millions of people around the world were vaccinated in an effort to eradicate this infectious disease, which had caused countless deaths over the centuries. The vaccine, administered on a massive scale until the late 1970s in many countries, left an unmistakable mark because of the way it was given.
