The extraordinary inside story of the biggest scientific challenge of our age - following a small band of vaccine scientists around the world who took on Covid-19 and ultimately delivered the weapon to beat it. As news of the coronavirus broke around the globe, a small group of scientists jumped into action to tackle one of the greatest medical challenges of our time: to create a vaccine against a virus no-one had ever seen before and to do so in record time, all during a deadly, global pandemic.