Bill Gates Considers This 'One Of The Most Important Achievements' In Human History

Bill Gates has touched on what he described as one of mankind's "most important achievements" in history.

What Happened: The billionaire tweeted on a day when the 33rd World Health Assembly declared the planet free of Smallpox back in May 1980.

"Eradicating smallpox was hard, but it was also one of the most important achievements in human history. That makes it worth celebrating—and learning from," said Gates.

Gates also shared a Vox article that touched on the eradication of the deadly viral disease among humans. The declaration was made on May 8, 1980.

The immunizing effect of the cowpox infection was discovered in 1796 and countries had an uphill battle since then to make the inoculation available. The U.S. Congress made the smallpox vaccine available through legislation in 1813, according to the report.

Why It Matters: Humans were devastated by Smallpox for nearly 3000 years. The first vaccine against the disease was invented by Edward Jenner, according to the World Health Organization.

 In 2016, Gates said that "very few people thought we would ever eradicate Smallpox."

Gates has on more than one occasion praised U.S. physician William Herbert Foege who the philanthropist termed as one of his heroes.

"He was instrumental in ridding the world of smallpox, which is still the only human disease ever eradicated," said Gates in a blog post in 2011.

At the time Gates recommended the book "House On Fire: The Fight To Eradicate Smallpox" by Foege.

"Bill was a mentor to Melinda and me in the early days of our philanthropy, and he continues to give us great advice today," said Gates.

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