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.

Of all the diseases that plague humankind, malaria has put up one of the longest, toughest fights. More than 200 million people fall ill and 600,000 die of it every year, making it among the world’s deadliest diseases. The vast majority of those fatalities are young children - an average of one child every minute. But medical science may now be at an exciting turning point.
Filmed with intimate access to key scientists on four continents, this documentary tells the inside story of the development of a new malaria vaccine that could change the very nature of the fight. It's hoped that the vaccine, dubbed R21/Matrix-M and developed by many of the same team behind the Oxford/AstraZeneca Covid-19 vaccine, will be the first to meet the World Health Organization’s target of 75 per cent efficacy.