Monitoring the rise of the SARS-CoV-2 lineage B.1.1.7 in Tenerife (Spain) since mid-December 2020

Starting in December 2020, a sharp increase of COVID-19 cases occurred in Tenerife compared to the rest of the Canary Islands (Spain). Because of the direct touristic connections between Tenerife and the UK, and the rapid transmission and dominance of the SARS-CoV-2 B.1.1.7 variant of concern (VOC-202012/01) by the end of November 2020 in South England, here we measured the proportion of B.1.1.7 cases occurring between the 18 th of December 2020 and the 25 th of February 2021. Out of the 2,091 COVID-19 positive nasopharyngeal swab samples assessed, 226 showed a spike gene target failure (SGTF). Subsequent viral genome sequencing further confirmed that 93.2% of them corresponded to the B.1.1.7 lineage. Furthermore, a rapid increase in the proportion of SGTF variants was detected in up to 10.7% of positive cases during the Christmas season despite stricter measures for containing the transmission were imposed in Tenerife in the period. These results support the local transmission of SARS-CoV-2 B.1.1.7 lineage in Tenerife since late December 2020 although it is not yet dominant.