 Abstract coronavirus disease 2019 COVID-19 caused by severe acute respiratory syndrome coronavirus 2 SARS-CoV-2 is an ongoing global health emergency. Here we highlight nine most important research questions concerning virus transmission asymptomatic and pre-symptomatic virus shedding diagnosis treatment vaccine development origin of virus and viral pathogenesis. This article was authored by Kit Sen Yuan, Zi, Wei Yi, Xin Yi Feng and others.