ABSTRACT
Effective responses to public health emergencies should rely on translating rapidly emerging research into timely, evidenceinformed policy and practice. The case of COVID-19 demonstrates that doing so in practice is far from straightforward. Evidence uncertainty;the "infodemic";the blurring of boundaries between science, policy and politics;and the competition between health and economic objectives, all make policy making for COVID-19 immensely complex. This article reviews these challenges and some of the tools countries have used to translate evidence into public health policy, not least multidisciplinary scientific advisory groups, which have often proved pivotal in informing government decision-making. Despite their emphasis on science and objectivity, however, they have posed questions about independence and transparency. This article explores what this means for the way decision-makers use evidence now and in the long-term, and for the role of neutral "knowledge brokers".