At the Global Vaccine Summit in Abu Dhabi late last week, the world's two richest men made a bit of philanthropic history. Carlos Slim announced his foundation will donate $100 million to the Global Polio Eradication Initiative, a new effort organized by the Gates Foundation to eliminate polio.

Including financial pledges from countries around the world, the conference raised $4 billion for the new strategy to achieve a polio-free world by 2018. That's enough to protect more than one billion children from polio forever.

$335 million of the $4 billion came from private philanthropists and billionaires, including New York Mayor Michael Bloomberg, who also gave $100 million.

Countries like Norway, Canada, Germany, Ireland, and the UK each made generous pledges, as did His Royal Highness the Crown Prince of Abu Dhabi.

The Gates Foundation stepped in with $1.8 billion, a third of what's needed for the polio campaign, saying, "Collectively, we sent a powerful message that the world remains committed to fulfilling the vision to end polio and reach all children, no matter where they live, with the vaccines they need."

(READ the story at Forbes.com)