Molecular characterisation of SARS-CoV-2 Delta variant circulated in Northern Vietnam during COVID-19 outbreak, 2021

Abstract

Vietnam reported its first case of COVID-19 infection from Wuhan - China in January 2020. In late 2020, the emergence of variants that pose an increased risk to global public health has prompted Characterization of Variants of Interest (VOI) and Variants of Concern (VOC) for appropriate responses to the COVID-19 pandemic. Since January 2020, National Influenza Center - National Institute of Hygiene and Epidemiology has been monitoring SARSCoV-2 and virus variants from the original Wuhan strain, variants originating from Europe, Alpha variant. This study was conducted to determine the genetic characteristics of the SARS-CoV-2 Delta variant circulating in Northern Vietnam in 2021. The results show that the Delta variant circulating in Northern Vietnam has ten sub-variants. The specific mutations D142G on S protein, P308S on ORF1a, along with other mutations create the SARS-CoV-2 AY.57 strain circulating in Northern Vietnam. The circulated viruses could form groups which had highly similar genetic sequences and show overlap in the geographical origin of the samples.