Dr Chris van Tulleken, Dr Hannah Fry and Michael Mosley examine the latest research and explore some of the big questions about Covid-19 and the pandemic it has created. Michael visits the UK government's high-security laboratory Porton Down, where vaccines are being tested. He also uncovers what the experience of the 2002 SARs epidemic reveals about this one. Both were caused by coronaviruses, but certain key changes to today's virus have allowed it to infect the world, where SARs was contained.

Did China hide crucial information about Covid-19 from the world? What began with a handful of mystery pneumonia cases in Wuhan late last year has now left more than half a million dead worldwide. Beijing says it has been open and transparent throughout, but former BBC China Editor Carrie Gracie investigates how it delayed reporting the initial outbreak and evidence that Covid-19 could be spread by people. It also silenced doctors who tried to speak out.
The film also hears from one high-level insider who believes the animal market at the centre of the Wuhan outbreak should have been treated as a 'crime scene' and from experts who warn that this crisis may be a 'dress rehearsal' for an even more deadly pandemic in the future.

How can we cope with the tricky coronavirus now rampant worldwide? As the pandemic tightens its grip on the world, there are important unanswered questions about this novel virus: Why does this infection spread so rapidly from people with no symptoms? Why do some people become critical while others don't? Will a definitive treatment be found? The underlying key to these questions lie in our immune system. Immune cells are microscopic warriors, combating viruses and another pathogens.
Through the high-tech 'eyes' of next-generation microscopes and computer-generated imagery, we will see how our immune defense corps combat against microbes and what mechanism is expected to help develop treatment.

COVID-19 is far from the first pandemic to wreak havoc in the world. A long line of infectious diseases have devastated and in some cases destroyed entire societies. Almost all of them started in animals and made the jump to humans. The Black Death spread across Europe and Asia in the 14th century leaving millions dead in its wake. Between the 15th and 18th centuries, European colonists brought smallpox to the Americas, the Pacific region and to Australia. In Europe, the 17th century saw a series of major epidemics. And at the end of the First World War, more people died of the Spanish flu than on the battlefield.
This documentary examines the causes of these epidemics - whether it be lack of hygiene, interaction with animals, overcrowding, or the growth of cities - and how people travelling helped to spread disease and promote pandemics. It also sheds a light on the impact these infectious diseases have had on politics and societal change. Over the centuries, scientists managed to develop treatments and medicines to help control or even eradicate infectious diseases. Virologists are facing that task again with the coronavirus, as the world frantically searches for ways to overcome a pandemic which threatens our modern way of life.

With a million species at risk of extinction, Sir David Attenborough explores how this crisis of biodiversity has consequences for us all, threatening food and water security, undermining our ability to control our climate and even putting us at greater risk of pandemic diseases.
Everything in the natural world is connected in networks that support the whole of life on earth, and we are losing many of the benefits that nature provides to us. The loss of insects is threatening the pollination of crops, while the loss of biodiversity in the soil also threatens plants growth.
Last year, a UN report identified the key drivers of biodiversity loss, including overfishing, climate change and pollution. But the single biggest driver of biodiversity loss is the destruction of natural habitats. Seventy-five per cent of Earth's land surface (where not covered by ice) has been changed by humans, much of it for agriculture, and as consumers we may unwittingly be contributing towards the loss of species through what we buy in the supermarket. Human activities like the trade in animals and the destruction of habitats drive the emergence of diseases. Disease ecologists believe that if we continue on this pathway, this year’s pandemic will not be a one-off event.

It is 1918 and the end of WWI. Millions have died, and the world is exhausted by war. But soon a new horror is sweeping the world, a terrifying virus that will kill more than fifty million people - the Spanish flu. Using dramatic reconstruction and eyewitness testimony from doctors, soldiers, civilians and politicians, this one-off special brings to life the onslaught of the disease, the horrors of those who lived through it and the efforts of the pioneering scientists desperately looking for the cure.
Narrated by Christopher Eccleston, the film also asks whether, a century later, the lessons learnt in 1918 might help us fight a future global flu pandemic.