Pfizer has come up trumps. Now that a vaccine for Covid-19 is more than just a possibility, we can breathe a collective sigh of relief. But before we relax too much, a new problem arises: will people actually take it?

A third of people in the UK – and half of people in the United States – say they are either uncertain or unlikely to agree to be vaccinated against coronavirus, according to research from the Royal Society and the British Academy.