Nextstrain's daily-updated tree of SARS-CoV-2 genomes was my gateway into the world of viral phylogenetics in early 2020, and Nextstrain's beautiful interactive tree display is crucial to making usher.bio results usable. GISAID cutting off data harms global surveillance efforts. 🧵👇
On Oct 1, 2025, GISAID informed us that they had ended updates to the flat file of SARS-CoV-2 genomic sequences and associated metadata that we had used to update Nextstrain analyses since Feb 2020. GISAID's stated rationale was that their "resources are limited". 1/5