Witness

In 1985 activists hand-stitched a giant quilt to commemorate friends and relatives killed by AIDS, and to campaign for more funding and research into the disease. It was the brain child of Cleve Jones, who explains to Rebecca Kesby what it was like to live through the HIV/AIDS epidemic in San Francisco. How the LGBT community had to pull together, as victims of AIDS were ostracised by the wider community during their worst moment of suffering. (Photo: A section of the AIDS Memorial Quilt. Getty Images)

On March 26th 2010 a South Korean naval ship, the Cheonan, sank after an explosion on board. 48 sailors were killed in an alleged torpedo attack carried out by North Korea. The North Korean authorities have always denied any involvement. Bugyeong Jung has been speaking to a survivor of the attack about what happened that night. Photo: A giant floating crane lifts the stern of the South Korean warship to place it on a barge on April 15, 2010. The 1,200-tonne patrol combat corvette PCC-772 Cheonan was split in two by a big external explosion on March 26 2010, near a disputed Yellow Sea border. Credit: HONG JIN-HWAN/AFP via Getty Images

On the night of March 25 2015 Saudi Arabia and its allies launched an intense aerial bombardment of the Yemeni capital Sana'a. The attacks pushed one of the poorest countries in the Arab world to breaking point. Sumaya Bakhsh has been speaking to surgeon, Dr Ali al-Taifi, about his memories of that first night of bombing and the suffering that has carried on in Yemen ever since. Photo: citizens of Sana'a searching through rubble for survivors on morning of March 26th 2015, after the Saudi bombing. Credit: Getty Images.

Over 50 million people died from influenza during the 1918-19 influenza pandemic. Scientists trying to understand why that particular strain of flu was so virulent, dug into Alaska's permafrost to find traces of it to study. Kate Lamble has been speaking to Dr Jeffery Taubenberger who sequenced the genome of the so-called "Spanish" flu virus. Photo: an influenza ward in 1918. Credit: Hulton Archive/Getty Images.

In the 1970s, scientists in China used ancient traditional medicine to find a cure for malaria. Artemisinin was discovered by exploring a herbal remedy from the 4th century, and can cure most forms of malaria with very few side effects. It has saved millions of lives all over the world. Rebecca Kesby talks to Professor Lang Linfu, one of the scientists involved. PHOTO: Professor Lang Linfu (family archives)