How does one begin to write about an event with no clear beginning? Who can say whether the pandemic’s first spark—index case in epidemiological parlance—was in December 2019 or January 2020 or some earlier date? We may never truly know the exact minute when the world’s first human was infected with the novel SARS-CoV-2 virus—the causative agent of COVID-19.

Since starting to shelter in place in mid-March, I have been thinking about what it is I really want to say about this public health crisis. There are so many moving parts and so many people adding to the conversation. I could write about the biology and epidemiology of an infectious disease and how we might #flattenthecurve or practice #socialdistancing, or about the politics of division, denial and, fear. I could write about the add-on costs of unemployment, school closures, slowing of travel and trade, and the cessation of inter-country collaborations and partnerships that if in place may have helped overcome our shared pandemic challenge. However, as an epidemiologist and someone who has spent a career asking the how, what, where, why, and who of disease events, I ended with two questions. How did we get here? Where do we go from here? Before exploring these questions, it makes sense to consider what we do know about COVID-19.