Smallpox vaccine scars: What they look like and why

Smallpox was a deadly viral disease caused by the variola virus. It spread easily and killed about 30% of those infected, leaving survivors scarred for life. For centuries, it devastated populations around the world.

Thanks to global vaccination campaigns, smallpox became the first disease ever eradicated. The World Health Organization (WHO) declared it eradicated in 1980, and routine vaccinations in the U.S. stopped years earlier, in 1972.

The smallpox vaccine was unlike most modern vaccines. It used a bifurcated needle, a small two-pronged instrument dipped into the vaccine solution. The skin was pricked several times quickly, introducing the vaccine into the dermis.

The vaccine contained a live virus called vaccinia, related to smallpox but far less dangerous. After vaccination, a blister formed, then scabbed and healed, leaving behind the distinctive circular scar recognized around the world. Continue reading…