On the road to halting HIV

An injectable antiviral "PrEP" therapy that gives 100% protection against HIV infection. Trials among young women in South Africa and Uganda proved so effective, they were wound up early to accelerate its use. Linda-Gail Bekker of the Desmond Tutu HIV Foundation shares her excitement. A new kind of gene therapy that uses the cell's own “epigenetic” mechanisms to silence troublesome portions of our DNA, tested against the prion protein responsible for some brain diseases. Jonathan Weissman led the research at the Whitehead Institute for Biomedical Research in Massachusetts. Accelerated evolution is being tested in Matthew Nitschke’s labs in the Australian Institute for Marine Science to see if it can help protect natural corals against future global warming. The amazing 4.200 km transatlantic flight of some Painted Lady butterflies – and the extraordinary detective work ecologist Gerard Talavera and team needed to prove it. Presenter: Roland Pease Producer: Jonathan Blackwell Production Coordinator: Jana Bennett-Holesworth(Image: HIV Vaccine Efficacy Trial Conducted In Uganda. Credit: Luke Dray / Stringer via Getty Images.)