The devastating effects of COVID-19 and the speed of both the scientific and medical response and the public information requirements about frontline healthcare work, medical advances and policy and compliance measures has necessitated an intensity of science communication never seen before. This JCOM special issue — the first of two parts — looks at the challenges of communicating COVID-19 and coronavirus in the early spread of the disease in 2020. Here we present papers from across the world that demonstrate the scale of this challenge.