The UK could carry out Covid ‘challenge trials’, where healthy volunteers are deliberately infected with coronavirus to test possible vaccines. Challenge studies were used to test vaccines for flu, cholera and typhoid, but there were treatments to prevent volunteers from falling ill. Coronavirus trials have the added risk that should volunteers become unwell, the only drugs available will control the disease not remove it. University student Alastair Fraser-Urquhart will volunteer if the trial goes ahead. He said, ‘I think it might save thousands of lives and bring the world out of the pandemic sooner.’ Professor Peter Horby said the trials have the potential to advance science and help us to better understand coronavirus. ‘The risk in a healthy young adult with no underlying conditions is extremely low. What's been holding things up are ethical considerations.’