Mu SARS‐CoV‐2 (B.1.621) variant: A genomic snapshot across the Colombian‐Venezuelan border

Abstract

The COVID-19 pandemic has resulted in the emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, including the Mu variant (B.1.621), first identified in Colombia in January 2021. 1 This variant exhibits a distinct mutational profile, predominantly in the spike protein region 2 which impact the virus's ability to be recognized by antibodies from natural infection or vaccination. 3,4 Mu variant has been highly prevalent in Colombia, (https://outbreak.info/ location-reports?loc=VEN%26alias=Mu%26dark=true%26selected=Mu) and associated with a significant number of COVID-19-related deaths. 2 Investigations into its emergence and spread have been conducted in various Colombian departments and neighboring countries, including Venezuela, 5 where it was introduced through population displacement via the frontier with Colombia. 6 Despite the wellknown spread and dispersion of SARS-CoV-2 among both countries, few studies have assessed the epidemiological impact, genomic features, and phylogenetic relationship of the Mu variant in Colombian departments bordering the Western Venezuelan states with the highest prevalence of COVID-19 cases. This data is of utmost importance, particularly in context of the ongoing Venezuelan humanitarian and refugee crisis. Twenty-four SARS-CoV-2 positive samples collected between May 2021 and February 2022 were analyzed, with16 and 8 fromColombian and Venezuelan patients respectively. Whole genome analysis and lineage identification were performed as previously reported. 7 The sociodemographic characteristics of patients are included in Supporting Information: Table 1.Comparative genomics analysis was conducted to assess phylogenomic relationships of 24 genomes, these were compared against 18 111 Colombian genomes, 542 Venezuelan genomes and 2365 reference genomes (representative selection of all SARS-CoV-2