The roll out of Covid-19 vaccines has boosted hopes the virus can be tamed. But it will have to be worldwide effort if it is to be effective, and right now the signs aren’t good. While tens of millions have already been vaccinated in the rich west, the world’s poor are facing a very long wait. The phrase ‘vaccine apartheid’ has already been coined. Stephen Sackur speaks to the Chief Scientist at the World Health Organisation Dr Soumya Swaminathan. Is vaccine inequity undermining the fight against Covid?