Important Information on the Emerging ‘Eris’ COVID Variant

The new COVID-19 virus variant spreading now, “Eris,” is currently the predominant strain in the United States, according to data from the U.S. Centers for Disease Control and Prevention (CDC). Although it’s increasingly reported worldwide, health experts say it poses a low risk to public health, as there is no evidence it causes different or more severe symptoms than previous omicron offspring.

The Essentials

A subvariant of the omicron lineage, Eris, otherwise known as EG.5, was detected as early as February 2023.

As of Aug. 23, Eris has been detected in more than 50 countries and is responsible for an estimated 20.6 percent of all cases in the United States.

Meanwhile, FL.1.5.1 is now the second most prevalent strain, accounting for over 13 percent of cases.

On Aug. 9, the World Health Organization (WHO) designated Eris as a variant of interest (pdf), meaning it possesses genetic characteristics that could increase its transmissibility, virulence, and ability to evade vaccines.

The WHO had previously labeled Eris as a variant “under monitoring” after a surge in COVID-19 infections in early July.

The current variant of interest list also includes two other omicron cousins—XBB.1.5 and XBB.1.16.

If Eris is upgraded to a variant of concern, governments would need to increase preventative measures, such as mask mandates in hospitals, testing, or physical distancing.

There have already been growing concerns that Eris could trigger governments to revive some COVID-19 restrictions.

How Dangerous Is It Compared to Other Variants?

Eris is a descendent of omicron variant XBB.1.9.2.

Eris carries an additional amino acid mutation, known as F456L, in the spike protein. This mutation has been shown to escape immunity gained from previous variants and may help the new variant transmit quickly.

The CDC said there is no evidence Eris causes more severe disease than other omicron descendants, and it seems to cause similar symptoms.

Similar to those of earlier COVID-19 virus strains and that of the common cold, symptoms may include the following:

• Fatigue.
• Muscle pain.
• Chest pain.
• Headache.
• Sore throat.
• Runny nose.
• Congestion.
• Cough.
• Fever and chills.
• Nausea or vomiting.
• Diarrhea.
• Loss of taste or smell.

New Generation ‘Variant Under Monitoring’

Health authorities have also been tracking a highly mutated strain called BA.2.86, or “Pirola” by some, which has caught scientists by surprise after it was picked up by COVID-19 testing on three continents.

This variant has scientists on alert because its emergence is reminiscent of the early days of the omicron variant in late 2021 when researchers in southern Africa noticed a lineage that quickly spread globally.

“There’s a little bit of déjà vu all over again,” said Adam Lauring, a virologist and infectious-disease physician at the University of Michigan in Ann Arbor, whose lab identified one individual infected with BA.2.86, in an interview with Nature.

Health authorities first detected BA.2.86 in Denmark on July 24, and it has also been spotted in the UK, United States, and Israel.

None of the cases appears to be linked, including three infections in Denmark found in different parts of the country. This geographical distribution is another feature of BA.2.86 that is garnering scientists’ attention.

This suggests the variant may already be fairly widespread, Jesse Bloom, a viral evolutionary biologist at the Fred Hutchinson Cancer Center in Seattle, told Nature. “It’s got to have been transmitting a fair amount.”

The UK Health Security Agency said a recent case was reported in a person with no recent travel history, “suggesting a degree of community transmission within the UK.”

However, experts do not expect BA.2.86 to have the same impact as omicron due to response practice with earlier COVID-19 waves and vaccine rollouts. “There’s good reason to think it won’t be like the omicron wave, but it’s early days,” Mr. Lauring said in the Nature interview.

Current Vaccines

Pfizer, Moderna, and Novavax have created new versions of their vaccines to target another omicron sublineage—XBB.1.5—similar to Eris, so health authorities hope the vaccines will work on new variants.

However, according to the WHO, the F456L mutation Eris carries has been shown to decrease the neutralization of most XBB.1.5 neutralizing antibodies.

Listed by the WHO as a “variant of concern,” XBB.1.5 previously dominated transmission in the United States for several months straight but was surpassed by XBB.1.16, or Arcturus, in July.

The new CDC director, Dr. Mandy Cohen, anticipates that these vaccines will be available at common locations such as pharmacies and anticipates an annual COVID-19 shot, integrating it into routine health practices.