An urgent appeal has been issued for volunteers to take part in human trials of a potential coronavirus vaccine - with those who take part offered up to £625. Teams at the University of Oxford and Imperial College London are each getting at least another £20m of public money after making "rapid progress" in the hunt for a COVID-19 vaccine, Health Secretary Matt Hancock has said. With Oxford's clinical trials due to begin on Thursday, Sky News looks at who is eligible to take part and how can people get involved.