When Professor Adrian Hill, the scientist leading the Oxford Covid-19 vaccine programme, suggested that vaccine trials should deliberately expose young, healthy volunteers to coronavirus, he faced opposition from some of his colleagues. Newspapers were told that senior research partners were “not particularly happy” with Hill. Professor Sarah Gilbert, a senior vaccinology expert at Oxford, later delivered a humiliating public slap-down: “It’s not something that’s going to happen in the short-term,” she told BBC Radio 4.