How has maths been used in the fight against Covid-19? Maths vs. Covid-19 #GreshamLecture Mathematics has been used as a tool to understand and control infectious disease for over a century, but Covid-19 brought along a whole epidemic of new challenges. In this joint lecture with the London Mathematical Society we will see some of the maths used in the fight against the pandemic, and also hear some insights into life as a mathematician assisting with policy advice during this unprecedented time.