TECHNOLOGY × HUMAN EVOLUTION

The First Vaccine

1796 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

Giving someone a mild disease caught from cattle, on purpose, to protect them from a deadly one caught from people. It worked a century before anyone knew what a virus was, and the reason it worked took longer still to understand: the two diseases are close enough that the immune system mistakes one for the other.

Why it matters

Inoculating with smallpox itself was old, and killed a share of those who took it. Using a milder relative made protection survivable, and therefore repeatable, and therefore something an entire population could receive. That is what turned a treatment into a campaign, and the campaign worked: smallpox is the only human disease we have ever deliberately eradicated.

Dating & uncertainty

Inoculation with smallpox itself was practised in Asia and Africa long before. What 1796 marks is not the idea of inoculating but the turn to a milder related disease, cowpox.

Sources

1. Riedel (2005), Proceedings (Baylor University Medical Center) · Edward Jenner and the history of smallpox and vaccination
2. Ahamed & colleagues (2024), Cureus · Jenner's legacy: how Edward Jenner's smallpox vaccine changed public health
3. Foege (1998), Bulletin of the World Health Organization · Smallpox eradication in west and central Africa revisited

Earth history as one day

23:59:59.99564.4 ms before midnight

if Earth’s 4.54 billion years were compressed into a single day