The race is on for a Covid-19 vaccine. It’s as urgent as a sprint, but requires the meticulous preparation of a marathon. Then there are hurdles to overcome - perhaps more like a steeplechase. The race began in January with the identification of the SARS-Cov2 genome. By March, the first vaccine safety trials on humans began. And the pandemic took a tighter and tighter hold on the world. Ten vaccines are now in the final phase of testing.