Ian Sample talks to Prof Alan Melcher of the Institute of Cancer Research about how personalised cancer vaccines work and whether they could one day be used to to target cancer before it is even detectable on scans

Guardian Seascapes reporter Karen McVeigh tells Madeleine Finlay about a recent trip to the Galápagos Islands, where mounds of plastic waste are washing up and causing problems for endemic species. Tackling this kind of waste and the overproduction of plastic were the topics on the table in Ottawa this week, as countries met to negotiate a global plastics treaty. But is progress too slow to address this pervasive problem?