Trials of experimental coronavirus vaccines are already under way, but it’s still likely to be years before one is ready and vaccination may not even be possible
It is far from guaranteed that the vaccine will be safe and effective. 2013 study calculated that, before entering clinical trials, the average experimental vaccine has a 6 per cent chance of ultimately reaching the market. Of those that make it into trials, a 2019 analysis suggests the probability of success is 33.4 per cent.