Fig 2. SARS-CoV-2 lineage diversity in Switzerland and neighbouring countries during the study period from the first detected case on February 26^th to March 23^rd 2020, divided into four weeks (I: February 26^th–March 3^rd, II: March 4^th - 10^th, III: March 11^th - 17^th, IV: March 18^th - 23^rd (6 days)).

A. Daily cases and lineage identity in the Basel area cohort. Low-abundant lineages increased one week after the end of winter school vacation (March 8^th) and were introduced by travel returners. B. SARS-CoV-2 lineage diversity in the Basel area, the rest of Switzerland, and neighbouring countries. Number of genomes per week are represented in the inner margin of the time wheel. Number of lineages (L) per country counted from onset of the epidemic in each country until March 23^rd 2020. Link to the baselayer: https://ec.europa.eu/eurostat/web/gisco/geodata/reference-data/administrative-units-statistical-units/nuts.