Singer Elton John, Secretary of State Hillary Clinton and Microsoft co-founder Bill Gates are among those addressing the AIDS 2012 Conference, which opened Sunday at the Washington Convention Center.

President Barack Obama recorded a video welcoming attendees to the conference.

“On behalf of Americans everywhere, welcome to the 2012 International AIDS Conference and thank you for your commitment to achieving an AIDS-free generation here in America and around the world,” Obama said in the 3-minute video. “We've made great progress, but there is still a lot of work to do. So, let's move forward together.”

In her speech, Clinton reiterated the administration's resolve to find a cure for AIDS.

“The United States is committed and will remain committed to achieving an AIDS-free generation,” Clinton told attendees. “We will not back off, we will not back down, we will fight for the resources necessary to achieve this historic milestone.”

During a panel discussion, Gates, whose Bill and Melinda Gates Foundation has invested $10 billion toward finding an AIDS vaccine, said a vaccine would be “the ultimate tool.”

“Scientists are making great progress, they understand the shape of the virus, how to generate antibodies,” Gates said.

Elton John, whose Elton John AIDS Foundation gives away $18 million a year, said the AIDS epidemic is “fueled by stigma, by hate, by misinformation, by ignorance, by indifference.”

“Yes, I hope and pray that we will all discover a vaccine, we all do. But we won't get that vaccine to those in need if governments shun their most marginalized citizens. That is why compassion is critical. That is why love is the cure.”