Why was smallpox vaccination a major advance in medical history?

Smallpox vaccination was a monumental advancement in medical history because it provided a safe, effective method to confer immunity against a devastating, often fatal disease without the significant risks associated with earlier practices.12

Before Edward Jenner demonstrated the efficacy of the smallpox vaccine in 1796, the only available preventive measure was variolation—the deliberate infection of a person with material from a smallpox patient. While variolation offered protection, it was dangerous, as it could cause severe illness or death in roughly 2 percent of those inoculated, and it made the recipient contagious.2

Jenner’s discovery that infection with cowpox provided immunity to smallpox without the risk of contracting the deadlier disease transformed public health. This breakthrough eventually led to the World Health Organization’s global vaccination initiative, which resulted in the eradication of smallpox in 1980. This achievement remains a landmark in the history of vaccines and global disease control.314