Israel was a world leader when it started immunising its population last winter, but as cases started to rise in July, questions were raised about the future of the vaccination programme and the ongoing pandemic. Now, Israel’s booster vaccination programme, which offers a third shot to over-40s, has started to show signs of success. Early data suggests a tenfold increase in protection from infection and severe disease after the third jab, compared with after two. More widely, the country’s booster programme could provide more answers to some of the key remaining questions surrounding vaccines. Meanwhile, how fast are vaccines being rolled out globally?