Dynamics of SARS-CoV-2 variants of concern (VOC) in Bangladesh during the first half of 2021.

Bangladesh is the second-worst-affected country in South Asia by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this study is to examine genome sequences from Bangladesh from January 2021 to June 2021 in order to monitor the SARS-CoV-2 VOC and the clades or lineages that are prevalent in the country. Within the study timeframe, at least eight Nextstrain clades were found: 20A, 20B, 20C, 20H (Beta, V2), 20I (Alpha, V1), 20 J (Gamma, V3), 21A (Delta), 21D (Eta), and six GISAID clades: four main (G, GH, GR, GRY) and two minors (GV, O) with an introduction of VOC B.1.1.7/Alpha, B.1.351/Beta and B.1.617.2/Delta. The introduction and recent occurrence of VOCs with substantial alterations in the receptor binding site of spike protein (K417 N, K417T, L452R, T478K, E484K, S494P, N501Y) are of particular importance. Specifically, VOC B.1.617.2/Delta has surpassed all prior VOCs in Bangladesh, posing a challenge to the existing disease management.