New HIV infections globally in 2013: Sub-Saharan Africa continues to have the greatest numbers of new infections.
Vaccines developed over time.
Nural Choudhury
CNN
CNN
AIDS activists light a group of candles placed in the shape of a red ribbon during an event marking World AIDS Day in Manila on December 1, 2012.
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Balloons are released next to a sea of candles at the World Aids Day memorial in Berlin on November 30, 2011.
A red ribbon is hung between columns on the north side of the White House to commemorate World AIDS Day on November 30, 2010, in Washington.
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Volunteers from Red Cross China take part in an AIDS-awareness event on World AIDS Day in Beijing on December 1, 2009.
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A group of Chinese men gather to collect the free condoms distributed to mark World AIDS Day in Fujian province on December 1, 2010.
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Indian villagers hold oil lamps as they surround a huge AIDS symbol on the beach at Nalsarovar on November 30, 2009, the eve of World Aids Day.
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HIV-positive women make red ribbons, the universal symbol of awareness and support for those living with HIV, at a support center in Bangalore on the eve of World AIDS Day on November 30, 2012.
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A Pakistani technician takes samples in a laboratory alongside a ribbon promoting World Aids Day in Islamabad on November 30, 2013. Researchers in the United States believe there may finally be an HIV vaccine within 10 years.