by @Chris
How COVID-19 spread from a pneumonia cluster in Wuhan to every country, and how variants then took turns sweeping the world. Part 1 (Dec 2019 – Aug 2020) colours each country (provinces in China, regions in Italy, states in the US) by new confirmed cases per million in the 14 days before each date; a country first appears as a circle around the city of its first confirmed case. Part 2 (Oct 2020 – May 2023) colours each country by the variant that made up most of its sequenced samples in the previous four weeks; countries with too few sequences stay uncoloured. Confirmed cases depend on testing and undercount real infections, especially early on and in countries that tested little. Sources: WHO COVID-19 dashboard and Our World in Data (cases, deaths); JHU CSSE (China, Taiwan); The New York Times (US states); Protezione Civile (Italy); CoVariants.org / GISAID (variants); Wikipedia (first cases, events).
100–500 new cases per million in 14 days · 500+ new cases per million in 14 days · Cases reported (under 10 new cases per million in 14 days) · 10–100 new cases per million in 14 days · Dominant variant: Earlier lineages · Dominant variant: Alpha (B.1.1.7) · Dominant variant: Beta (B.1.351) · Dominant variant: Gamma (P.1) · Dominant variant: Other variants (Epsilon, Iota, Lambda, Mu…) · Dominant variant: Delta (B.1.617.2) · Dominant variant: Omicron BA.1 · Dominant variant: Omicron BA.2 · Dominant variant: Omicron BA.4 / BA.5 (incl. BQ.1) · Dominant variant: Omicron XBB