Smallpox is truly a disease out of a horror film.

Your body would erupt all over with fluid-filled bumps, both externally and internally, and 30% of those who caught smallpox died.

Over thousands of years of human history, this nightmarish disease killed the rich and the poor alike, from Egypt’s Pharaoh Ramses V to Louis XV of France to maybe even the Native American Pocahontas. Smallpox was one of the major reasons for the downfall of the Aztec empire.

As recently as the 20th century, as many as 500 million people died from smallpox — it killed more people than all of the wars in that century combined.

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The only tool to fight smallpox was a vaccination that prevented you from getting the disease in the first place.

The vaccine was first scientifically tested by the British physician Dr. Edward Jenner in 1796, after he and others observed that milkmaids exposed to cowpox developed immunity against smallpox. The smallpox vaccine was the first use of vaccination to control an infectious disease. It launched modern-day immunology.

In the beginning, there were many doubters.

The vaccine was decried as unnatural and dangerous. Rumors circulated that it could maybe even turn you into a cow.

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But as hundreds of thousands of lives were saved, communities and nations slowly began to embrace this life-saving tool.

Over the next two centuries, the scientific community figured out how to efficiently and cost-effectively produce the smallpox vaccine in larger quantities. By the middle of the 1950s, most of the developed world had eliminated smallpox.

Seeing that success, a band of doctors put forward a radical idea. They believed smallpox could literally be wiped off the face of the Earth. To achieve this goal, they launched the world’s first-ever global health campaign to attack the disease in its last stronghold: India.

Under the auspices of the World Health Organization, a diverse brand of rebel physicians and scientists moved to India to work with the Indian government.

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Image: flickr/Pan American Health Organization PAHO

This eclectic group included an elegant couture-wearing French physician, a Czech epidemiologist, a devout Christian who had spent his life in global health, and a young American anti-war protestor who had found his way to an Indian Ashram in the Himalayas.

Many in the establishment called them crazy, but, creating new models for public health engagement and breaking some rules along the way, they set out to do what had never been done before: eradicate a disease.

Critically, the Indian government joined hands with this unusual team, mobilizing 33,000 district health workers and 100,000 additional field workers in the largest public health campaign ever launched in a country.

This army of Indian health workers visited an estimated 100 million homes. In a time before cell phones and GPS, workers went door to door looking for smallpox. Every time they found a case, they vaccinated everyone around the affected person.

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In four years, smallpox was eradicated from the Indian subcontinent. Shortly thereafter, a disease that had been the scourge of mankind for thousands of years was consigned only to history books.

So, what does the lesson of smallpox eradication show us?

It shows us that sometimes the impossible really is possible if you dream big, work relentlessly, and yes… maybe break a few rules. It tells us that a diverse group of people, even in the middle of the Cold War, can link hands and cross divides to save lives. And it tells us that countries like India can lead the way. Because of that, I now watch with admiration as Prime Minister Modi declares that India will try and eliminate tuberculosis by 2025, five years ahead of global deadlines.

Finally, in an age when many take for granted the value of vaccination, the eradication of smallpox should remind us that millions of us are alive today because of vaccines.


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What the Eradication of Smallpox Taught Us About Vaccines

By Janet Tobias