As the most recent Chief Scientist at the World Health Organization Soumya Swaminathan was on the forefront of the international response to the COVID-19 pandemic. Because of her distinguished background in policymaking spanning more than 30 years of experience bringing science and evidence into the formulation of effective actions to address fundamental issues of public health, Dr Swaminathan brings a wealth of insights into a conversation about the lessons learned from the pandemic and how to prepare for the next one. Viruses against which we have no natural immunity will continue to be a major risk factor in coming years and, against the huge human and economic costs of COVID-19, we need to internalize those lessons and come together as one whole human family, preparing responses that will be science-based but that will also leave no one behind because we live in an interconnected world in which our health and the health of others are fully interdependent.