Immunity is much more than just the body's defences – it’s more like a “fantastic orchestra where we don't know all the members and instruments”. We can think about it at the level of individuals and their bodily mechanisms, but also at the level of society and the planet. Just as we look after our health, it’s important to look for ways to protect relationships, communities and the environment. Immunity reminds us that personal and global challenges are interconnected. How can immunity contribute to finding balance in today's challenging world? How can it lead us towards better care for the most vulnerable and new ways of protecting health? What are the philosophical implications of a new understanding of immunity? And what can the “new” immunity teach us about our history, the workings of society, relationships, and entire political systems?