<p>In Autumn 2025 a paper in South Korea was published that excited many a vaccine sceptic online. The paper claimed that receiving a vaccination against Covid19 was linked to a 27% increase in cancer risk. </p><p>However, when you dig into the data there is no evidence that the vaccine caused the cancer. We spoke to Professor Justin Fendos to explain why we cannot take this type of statistical analysis at face value. </p><p>Presenter: Tim Harford Producer: Lizzy McNeill Series Producer: Tom Colls Editor: Richard Vadon Production Coordinator: Brenda Brown Sound Mix: James Beard</p>