A new lineage ‘Eris’ of Covid-19 has been designated by the World Health Organization (WHO) as an interesting variant, although the risk to public health is assessed as low.
The variant, known as EG.5 or ‘Eris’, is related to an Omicron subvariant called XBB.1.9.2, and is growing in prevalence globally, including in the UK, China, and the US. It first appeared in February 2023.
All viruses, including SARS-CoV-2, the virus causing COVID-19, change over time. Most changes have little to no impact on the virus’s properties. However, some changes can affect the virus’s characteristics, such as how easily it spreads, the severity of the disease, or the performance of vaccines, therapeutic drugs, diagnostic tools, or other public health and social measures.
The WHO has updated its monitoring system and working definitions for variants of SARS-CoV-2, the virus causing COVID-19, to better align with the current global landscape of variants, to independently evaluate Omicron sublineages in circulation, and to classify new variants more clearly when necessary.
SARS-CoV-2 continues to evolve. Since the beginning of the COVID-19 pandemic, the WHO has identified several variants of concern (VOCs) and variants of interest (VOIs) based on their estimated potential for expansion and displacement of earlier variants, for causing new waves of increased circulation, and for the necessity of adjusting public health actions.