The World Health Organization designated the eta coronavirus variant as a variant of interest (VOI) which means it is less of a concern than the alpha and delta variants, which are categorized as variants of concern.

The first cases of eta coronavirus variant were detected in December 2020 in the UK and Nigeria, and as of 15 February, it had occurred in the highest frequency among samples in the latter country.

As of 24 February, 56 cases were found in the UK. Denmark, which sequences all its COVID-19 cases, found 113 cases of this variant from January 14 to February 21, of which seven were directly related to foreign travels to Nigeria.

The eta coronavirus variant was prevalent globally around March through May, but the number of cases gradually declined since then, according to GISAID, a global science initiative and primary source that provides open access to genomic data of influenza viruses.