Figure 2. Global dating of the first emergence of severe acute respiratory syndrome coronavirus 2 variants identified in reinfections, Madrid, Spain, March 2020–March 2021, with available sequences only for the second specimen (patients 11–22). The phylogeny includes the 3,339 genomes from Nextstrain (https://nextstrain.org), extracted from the Europe-focused subsampling, through April 2021. Dates of the first episodes of cases are indicated with vertical lines. Dates for global emergence for the variants involved in their second episodes (B.1.1.7 and B.1.177) are indicated with an arrow and correspond to their first descriptions in Spain (as documented in GISAID, https://www.gisaid.org): for B.1.177, June 16, 2020 (hCoV-19/Spain/IB-IBV-99010764/2020, accession no. EPI_ISL_691664) and for B.1.1.7, November 8, 2020 (hCoV-19/Spain/VC-IBV-98012610/2020, accession no. EPI_ISL_1060510). Only reinfection cases finally validated by short tandem repeat host analysis are included.