Newsday - Covid-19 vaccine: 'It will take until next year' - BBC Sounds

As large parts of the world prepare for a renewed increase in coronavirus cases, governments have pinned their hopes on the rapid development of a vaccine to provide a route out of the pandemic.

With two more large-scale vaccine trials announced in the Americas and South Africa, can you really speed up the process by trying with more and more people?

Professor Beate Kampmann, director of the Vaccine Centre at the London School of Hygiene and Tropical Medicine, explains the difference between vaccine trials and human challenge trials and gives her assessment of when we can hope for a vaccine that works.