The prospect of reduced vaccine potency from fast-spreading SARS-CoV-2 variants has spurred a global rush to increase genomic surveillance for the coronavirus. This is crucial for quickly identifying and tracking emergent strains. It can also pin down how transmission occurs between individuals more definitively than typical contact tracing can. As this article went to press, laboratories around the world had sequenced more than 610,000 SARS-CoV-2 samples; that number could well exceed one million by the end of the pandemic. In theory, these genomes could help us to understand the spread of the virus through communities and across the globe, allowing us to stall infections. In practice, such analyses reveal much less than they might do. Much of the analysis of these genome sequences is not done by public-health bodies. It rests on the initiative of academic researchers, many of them early in their careers, who cobble together software and analytical tools in their own time to find essential answers. Nextstrain1, an open-source project involving groups from Switzerland and the United States, is helping to coordinate these efforts. One of us (E.B.H.), a Nextstrain researcher, has been working to track variants since September 2020 (see https://nextstrain.org/ncov/global). Less than two hours after the spread of an alarming new variant (now called 501Y.V1, or B.1.1.7) was announced by the UK health minister in December 2020, E.B.H. had provided context for its key mutations in a series of tweets, and showed its progression in the United Kingdom and across Europe in the months before (see go.nature.com/3ptrya5). The Twitter thread became a key source of information on the new variant, and E.B.H.’s Christmas break was lost to crunching further sequences and briefing journalists.

Top