As a child, the author noticed a strange circular scar on their mother’s arm and later discovered it came from the smallpox vaccine. Smallpox was once a deadly, highly contagious disease that killed millions before global vaccination efforts wiped it out, with the World Health Organization declaring it eradicated in 1980.
Unlike modern shots, the smallpox vaccine used a special needle and a live virus that caused a blister, leaving a lasting scar. Today, that mark is rare and serves as a reminder of one of medicine’s greatest achievements—proof that science successfully defeated one of history’s most dangerous diseases.