These powerful talks offer ideas for rethinking—and hopefully stopping—the spread of HIV and AIDS.

A long time ago in New York City, Steve Addis stood on a corner holding his 1-year-old daughter in his arms; his wife snapped a photo. The image has inspired an annual father-daughter ritual, where Addis and his daughter pose for the same picture, on the same corner, each year. Addis shares 15 treasured photographs from the series, and explores ...

In this moving talk, documentary photographer Kristen Ashburn shares unforgettable images of the human impact of AIDS in Africa.

TED Fellow and journalist Evgeny Morozov punctures what he calls "iPod liberalism" -- the assumption that tech innovation always promotes freedom, democracy -- with chilling examples of ways the Internet helps oppressive regimes stifle dissent.

Emily Oster re-examines the stats on AIDS in Africa from an economic perspective and reaches a stunning conclusion: Everything we know about the spread of HIV on the continent is wrong.

For the last eight years, pop singer Annie Lennox has devoted the majority of her time to her SING campaign, raising awareness and money to combat HIV/AIDS. She shares the experiences that have inspired her, from working with Nelson Mandela to meeting a little African girl in a desperate situation.

In 2008, something incredible happened: a man was cured of HIV. In over 70 million HIV cases, this was a first, and, so far, a last, and we don't yet understand exactly how he was cured. But if we can cure people of various diseases, like malaria and hepatitis C, why can't we cure HIV? Janet Iwasa examines the specific traits of the HIV virus th...

Given $50 billion to spend, which would you solve first, AIDS or global warming? Danish political scientist Bjorn Lomborg comes up with surprising answers.

Seth Berkley explains how smart advances in vaccine design, production and distribution are bringing us closer than ever to eliminating a host of global threats -- from AIDS to malaria to flu pandemics.

What could you do with the world's smallest 3D printer? Klaus Stadlmann demos his tiny, affordable printer that could someday make customized hearing aids -- or sculptures smaller than a human hair.

The most successful female British pop musician in history, Annie Lennox has now committed herself to raising awareness of, and supporting actions against, the HIV/AIDS crisis in Africa.

A few things you've always wanted to know about sex: why we enjoy it, how to explain it, and, importantly, how flowers do it.

The world is getting closer to achieving one of the most important public health goals of our time: eradicating HIV. And to do this, we won't even have to cure the disease. We simply have to stop HIV from being transmitted until eventually it fizzles out. Philip A. Chan explores the preventive strategies helping us tackle HIV and the possibility...

Epidemiologist Seth Berkley is leading the charge to make sure vaccines are available to everyone, including those living in the developing world.

Emily Oster has a history of rethinking conventional wisdom.

Dear current and future daughters ...

How can mothers with HIV avoid passing it to their kids? In South Africa, Mitchell Besser tapped a new resource for healthcare: moms themselves. The program he started, mothers2mothers, trains new mothers to educate and support other moms.

Sunitha Krishnan is galvanizing India’s battle against sexual slavery by uniting government, corporations and NGOs to end human trafficking.

Danish political scientist Bjorn Lomborg heads the Copenhagen Consensus, which has prioritized the world's greatest problems -- global warming, world poverty, disease -- based on how effective our solutions might be. It's a thought-provoking, even provocative list.

Ernest Madu founded the Heart Institute of the Caribbean, a revolutionary clinic for cardiovascular diseases in Kingston, Jamaica -- revolutionary for offering first-class health care in a developing nation. His next stop: Nigeria.

In Elizabeth Pisani's latest book, she explores the "improbable nation" of Indonesia.

Through his William J. Clinton Foundation, former US President Bill Clinton has become a vital and innovative force for world change. He works in four critical areas: health, economic empowerment, citizen service, and reconciliation.

Kristen Ashburn's photographs bring us face-to-face with real people in desperate circumstances. Taking us to the intimate spaces of her subjects -- the victims of war, disaster, epidemic -- she elicits the sublime sadness and resolve of human beings in suffering.

In 1948, Spanish ophthalmologist Jose Ignacio Barraquer Moner was fed up with glasses. He wanted a solution for blurry vision that fixed the eye itself, without relying on external aids. The surgery he eventually devised was called "keratomileusis," and his technique focused on reshaping the cornea— what we now know as LASIK. So how does laser e...

Tobacco use remains the leading cause of preventable disease and death in the United States, killing more people each year than alcohol, AIDS, car accidents, illegal drugs, murder and suicide combined. Follow health policy expert Mitch Zeller into the murky depths of the tobacco industry as he details the sordid history of nicotine addiction -- ...

There is an epidemic of HIV, and with it an epidemic of bad laws -- laws that effectively criminalize being HIV positive. At the TEDxSummit in Doha, TED Fellow Shereen El-Feki gives a forceful argument that these laws, based in stigma, are actually helping the disease spread.

Steroids. They've caused global scandals. They're banned in most athletic competitions. Yet the same properties that help elite athletes and bodybuilders improve performance also make steroids valuable for treating many illnesses and injuries, such as AIDS and cancer. So if steroids are used as medicine, they must be safe to use recreationally, ...

In sub-Saharan Africa, HIV infections are more prevalent and doctors scarcer than anywhere else in the world. With a lack of medical professionals, Mitchell Besser enlisted the help of his patients to create mothers2mothers -- an extraordinary network of HIV-positive women whose support for each other is changing and saving lives.

Pastor Rick Warren is the author of The Purpose-Driven Life, which has sold more than 30 million copies worldwide. His has become an immensely influential voice seeking to apply the values of his faith to issues such as global poverty, HIV/AIDS and injustice.

Dr. Gary Slutkin spent a decade fighting tuberculosis, cholera and AIDS epidemics in Africa. When he returned to the US, he thought he'd escape brutal epidemic deaths. But he began to look more carefully at gun violence -- whose spread follows the same pattern as an infectious disease. His conclusion: We've reversed the impact of so many disease...