EG.5 (Eris) and BA.2.86 (Pirola) two new subvariants of SARS-CoV-2: a new face of old COVID-19

The World Health Organization announced the end of the Coronavirus Disease of 2019 (COVID-19) global health emergency on May 5, 2023. However, the reports from different countries indicate an elevation in the number of COVID-19-related hospitalizations and deaths through the last months. The subvariant XBB.1.5 (Kraken) was the cause of 49.1% of COVID-19 cases by the end of January 2023. Although, the subvariant EG.5 (Eris) has surpassed the XBB.1.5 recently. EG.5 is a close subvariant descending from XBB.1.9.2 subvariant of Omicron. EG.5.1 is a sublineage carrying two crucial spike mutations F456L and Q52H. Up to now, it is not well-established whether its infectivity, severity, and immune evasion have shown any change or not. Also, BA.2.86 another subvariant of Omicron descending from BA.2 bears over 30 mutations which could affect its infectivity and transmissibility.

Scopus, PubMed, Google Scholar, and Google were searched with six keywords up to 20 November 2023 and highly reliable research and reports were selected to refer to in this article.

This brief review aims to overview the most reliable data about EG.5 and BA.2.86 based on scientific evidence.

Based on the currently available data these two new subvariants have similar features with currently circulating variants of Omicron and are less immune evasive than ancestral SARS-CoV-2.