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

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 SARS-CoV-2 genome during the 4th wave of COVID-19 pandemic in Tehran, Iran in 2021.

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

We detected alpha and delta variants during the 4th 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.

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.