Epidemiologists don’t often hang out with rock stars, and not many of them can say they’ve played a part in eradicating a disease as deadly as smallpox. But Larry Brilliant isn’t your run of the mill public health official. He’s been warning about the dangers of a pandemic for years, and now that one is upon us, Tim Harford sat down to talk with him about how the world has handled the pandemic of 2020 and what we can hope for in 2021.