Genomic Diversity and Evolution of Identified SARS-CoV-2 Variants in Iraq.

Abstract

The COVID-19 pandemic caused by the SARS-CoV-2 virus continues to circulate worldwide, causing the deaths of millions of people. The continuous circulation of the virus, its genetic diversity, the emergence of new variants with increased transmissibility, and/or the capacity of the virus to escape from the immune system constitute a major public health concern. In our study, we aimed to characterize SARS-CoV-2 strains in Iraq from the first introduction until the end of 2023, and to identify their variants, lineages, clades, and mutation patterns. All published Iraqi full genome sequences (2020-2023) were obtained from Global Initiative on Sharing All Influenza Data (GISAID) and subjected to molecular characterization along with 19 samples of full genome sequences that were collected during the fifth and sixth waves of the SARS-CoV-2 pandemic in this study. Next-generation sequencing was performed using an Illumina MiSeq system, and phylogenetic analysis was performed for all the Iraqi sequences. Three established global platforms, GISAID, Nextstrain, and PANGO, were used for the classification of isolates into distinct clades, variants, and lineages. Six wave peaks of COVID-19 cases have been identified in Iraq, resulting in approximately 2,400,000 cumulative confirmed cases and more than 25,000 deaths. Our study revealed patterns of circulation and dominance of SARS-CoV-2 clades and their lineages in the pandemic waves in the country.