Comparison of Circulating Variants during the Beginning, Middle and the End of the 4th Wave of COVID-19 in Tehran Province, Iran in 2021

Background: Whole viral genome sequencing with next generation sequencing (NGS) technique is useful tool for determining the diversity of variants and mutations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study we have attempted to characterize the mutations and circulating variants of the SARSCoV-2 genome during the 4^th wave of COVID-19 pandemic in Tehran, Iran in 2021.

Methods: We performed complete genome sequencing of 15 SARS-CoV-2 detected from 15 COVID-19 patients during the 4^th wave of COVID-19 pandemic with NGS. Three groups of the patients at the beginning, middle and the end of the 4^th wave were compared together.

Results: We detected alpha and delta variants during the 4^th wave of the pandemic. The results illustrated a dominance of amino acid substitution D614G in spike, and the most frequent mutants were N-R203K, G204R, S235F, nsp12-P323L, nsp6-G106del, G107del and F108del.

Conclusion: The detection of the virus mutations is a useful procedure for identifying the virus behavior and its genetic evolution in order to improve the efficacy of the monitoring strategies and therapeutic measures.