Most of their discussion was a promotion of the goals of the Gates' new campaign for 2015, to sign up millions of people via email to press for clean water, better education, renewable energy and online banking in the developing countries.
But host Fareed Zakaria asked Bill Gates to make some science predictions for the next 15 years. He began talking about HIV and AIDS.
Gates noted that HIV treatment has come a long way from the 1980s and 1990s, when HIV would turn into full-blown AIDS within months, killing 100% of infected people.
"As you get people on treatment their viral level is vastly reduced so that reduces their infectiousness," he said.
But patients never really get cured of HIV, they have to stay on that treatment indefinitely. "Lifelong treatment is hard," Gates said. He predicted that the next step in treatment would be drugs that required "a one-year treatment period. After that you won't need treatment anymore."
"These tools will be invented in that 15 year period."
Jim Edwards