As rich nations celebrate the success of their Covid vaccination programmes, most people in Africa haven't even received one life-saving injection. As variants of the virus emerge from unvaccinated populations, Seyi Rhodes visits South Sudan to investigate the reasons behind vaccine inequality. Poor of non-existent distribution of the vaccine is only one problem as Rhodes meets many people convinced by claims that vaccines are deadly. As anti-vaxx sentiment grows amid a stalling rollout, Rhodes meets a pro-vaxx preacher in a refugee camp with a David-versus-Goliath task.