1 Min Read The Birth of Immunology: Smallpox and Cowpox
July 24, 2026The Birth of Immunology: Smallpox and Cowpox
July 24, 2026
Care Framework & Diagram
A country doctor, a milkmaid, and an experiment that changed human history
By the Editors Care Framework & Diagram
~1000 BCE
Long before vaccination, people in China and the Middle East practiced ‘variolation’ — deliberately inoculating with pus from mild smallpox cases. Partially effective, but genuinely dangerous.
Long before vaccination, people in China and the Middle East practiced ‘variolation’ — deliberately inoculating with pus from mild smallpox cases. Partially effective, but genuinely dangerous.
May 14, 1796 — Modern Vaccinology Is Born
Edward Jenner takes cowpox pus from Sarah Nelmes and inoculates 8-year-old James Phipps. Six weeks later, he deliberately exposes the boy to smallpox itself. James Phipps does not get sick.
1798
Jenner publishes his findings and coins the word ‘vaccination’ — from the Latin vacca, meaning cow.
Early 1800s
Napoleon has his entire army vaccinated; multiple countries begin mandating it.
1959–1980
WHO launches and completes a global eradication campaign. On October 26, 1977, Somalia records the last natural case in history — the patient recovers.
May 8, 1980
WHO officially declares smallpox eradicated — the only disease ever eliminated by human vaccination. 184 years after Jenner’s experiment.
ONE LOOSE THREAD REMAINS
- Smallpox virus samples still exist at only 2 WHO-authorized sites (Atlanta, USA and Novosibirsk, Russia) — whether to preserve or destroy them remains internationally debated.
Frequently Asked Questions
Was Jenner the first person to use a vaccine? What about variolation?
Jenner was the first to use a 'weakened related pathogen' (cowpox, not smallpox itself) to generate protection, and the first to systematically document and publish his findings. Before Jenner, China and the Middle East had the practice of 'variolation' — directly inoculating healthy people with pus from mild smallpox cases. Though effective, the risk was high (about one to two percent chance of actually getting smallpox and dying). Jenner's cowpox vaccination was far safer than variolation, and represents the true starting point of modern vaccines.
What happened to James Phipps later?
James Phipps lived to age sixty-five (1788–1853), outliving Jenner. Jenner built a cottage in his own garden for the Phipps family as a gesture of gratitude, and the two families maintained lifelong friendly relations. After Phipps reached adulthood, Jenner challenged him with smallpox inoculation at least twenty more times — each time without infection — using this as proof of the vaccine's long-term effectiveness.
Is smallpox truly completely eradicated? Where does the virus exist now?
Yes, smallpox in nature has been eradicated. But currently two officially recognized smallpox virus sample storage sites remain: the CDC in Atlanta, USA, and the VECTOR Institute in Novosibirsk, Russia. These samples, per WHO decision, are kept for research purposes (developing better vaccines and treatments), but their fate — continue storing or ultimately destroy — remains an ongoing topic of discussion in international public health.
If smallpox reappeared today, could we handle it?
Far better than before 1980. We have stockpiled smallpox vaccines (though natural immunity now barely exists); a specific antiviral drug for smallpox (Tecovirimat, FDA approved in 2018); and more advanced infectious disease surveillance and emergency systems. The greatest vulnerability is that people born after 1980 (roughly half the global population) have never been vaccinated against smallpox and theoretically have zero immunity — which is why smallpox virus storage and management remains a serious topic in international security.