Pfizer Inc said on Thursday its updated COVID-19 shot, which is being tested against emerging variants, showed neutralizing activity against the "Eris" subvariant in a study conducted on mice.

Pfizer, along with its German partner BioNTech SE, as well as other COVID-19 vaccine makers Moderna and Novavax have created versions of their shots, which are aimed at the XBB.1.5 subvariant.

EG.5, nicknamed by some as "Eris", is similar to the XBB.1.5 subvariant and a sub-lineage of the still-dominant Omicron variant.

EG.5 accounted for about more than 17% of COVID-19 cases in the United States, according to the latest government data.

NEW COVID SUBVARIANT, ERIS, IS NOW MOST COMMON AND FASTEST-SPREADING IN US: 'NEVER GOING AWAY'

In the United States, COVID-19 related hospitalizations are up more than 40% off of recent lows hit in June, but are still more than 90% below peak levels hit during the January 2022 Omicron outbreak.

EG.5 has also been detected in China, South Korea, Japan and Canada, among other countries.

The World Health Organization classified EG.5 as a "variant of interest", indicating that it should be more closely watched than others because of mutations that might make it more contagious or severe.