Mathematical models as public troubles in COVID-19 infection control: following the numbers

Mathematical models are key actors in policy and public responses to the COVID-19 pandemic. The projections from COVID-19 models travel beyond science into policy decisions and social life. Treating models as ‘boundary objects’, and focusing on media and public communications, we ‘follow the numbers’ to trace the social life of key projections from prominent mathematical models of COVID-19. Public deliberations and controversies about models and their projections are illuminating. These help trace how projections are ‘made multiple’ in their enactments as ‘public troubles’. We need an approach to evidence-making for policy which is emergent and adaptive, and which treats science as an entangled effect of public concern made in social practices. We offer a rapid sociological response on the social life of science in the emerging COVID-19 pandemic to speculate on how evidence-making might be done differently going forwards.