While not conclusive, the two cases are "quite promising," says Anthony Fauci, a longtime AIDS researcher who directs the National Institute of Allergy and Infectious Diseases. Alex Wong/Getty Images hide caption

itoggle caption Alex Wong/Getty Images

When Benta Odeny was diagnosed with HIV, she started to protect her husband Daniel from the virus by taking antiretroviral medications. The same drugs also helped her give birth to an HIV-negative daughter, Angelia. Gregory Warner/NPR hide caption

itoggle caption Gregory Warner/NPR

A mother waits with her child at an HIV clinic in Nyagasambu, Rwanda, in February 2008. The clinic was built with a grant from the President's Emergency Plan for AIDS Relief initiative. Shashank Bengali/MCT /Landov hide caption

itoggle caption Shashank Bengali/MCT /Landov

President Obama walks into an auditorium in the Eisenhower Executive Office Building Monday for a speech about World AIDS Day. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP

One experimental condom has tabs on either side so it's easier to put on in the dark. Courtesy of California Family Health Council hide caption

itoggle caption Courtesy of California Family Health Council

HIV-positive babies rest in an orphanage in Nairobi, Kenya. Treatment right after birth may make it possible for HIV-positive newborns to fight off the virus. Brent Stirton/Getty Images hide caption

itoggle caption Brent Stirton/Getty Images

David Lozano (left) and Kevin Kreinbring stand in front of a painting created by Lozano. The couple says they get tested for HIV together every six months. Courtesy of David Lozano hide caption

itoggle caption Courtesy of David Lozano

A doctor takes an HIV test from an athlete during the 18th National Sports Festival in Lagos, Nigeria, last December. Sunday Alamba/AP hide caption

itoggle caption Sunday Alamba/AP

Latinos and African-Americans are more active on social media. Could that help promote HIV testing among minorities? Brendan Smialowski/Getty Images hide caption

itoggle caption Brendan Smialowski/Getty Images

A prostitute in Johannesburg waits for a client on a street corner. An estimated two-thirds of sex workers in South Africa are HIV positive. Yoav Lemmer/AFP/Getty Images hide caption

itoggle caption Yoav Lemmer/AFP/Getty Images