More than a 100 million people around the world have received a jab for Covid 19. But, we’re greedy - we want more. The virus is mutating, so vaccinations need to happen faster. And our vaccines are good, but will have to get better. Economists like to talk about incentives to get products to market faster, but will these tools that will work for the development of vaccines? This week Tim Harford puts this question to Professor Michael Kremer, winner of the Nobel Memorial Prize in Economics, Anna Mouser of the Wellcome Trust and Patrick Tippo of Biovac in South Africa. Producers: Sandra Kanthal and Josephine Casserly Listener Questions can be sent to: [email protected]