A new COVID-19 subvariant has arrived. Here's what we know about Eris

The new subvariant is fast becoming one of the most prevalent in the United Kingdom and United States. Experts say the same thing could happen in Australia.

A new subvariant of the Omicron COVID-19 strain has emerged, dubbed Eris, or EG.5.1. Source: AAP / Joel Carrett

Key Points

• Subvariant EG.5.1, or Eris, is increasingly appearing in COVID-19 cases in the United States and United Kingdom.
• Experts say it's likely a similar pattern will emerge in Australia.
• Symptoms of the subvariant reportedly include a runny nose, headache, fatigue, sneezing and a sore throat.

The coronavirus pandemic is no longer considered a global health emergency, but strains of the virus continue to develop and evolve.

Now, one new subvariant is causing a spike in cases in some parts of the world, and experts believe it is likely already circulating in the Australian community.

Here's what we know.

What do we know about the Eris COVID-19 variant?

The new coronavirus variant has been dubbed Eris, or EG.5.1, and was reportedly first detected in Asia.

It is part of the Omicron sublineage and part of the EG.5 group, which was listed as a variant under monitoring by the World Health Organization in July.

Associate professor Paul Griffin, an infectious disease physician and clinical microbiologist, believes the subvariant has likely made its way to Australia, but has not yet been officially identified due to limited testing being done.

He said Eris appears to be on the rise around the world.

"It has certainly increased, with an estimate that it has perhaps doubled in prevalence in the last four weeks or so globally from nearly six to twelve per cent (of cases)," he said.

"It does look like it may be becoming the dominant subvariant of Omicron in a number of countries."

EG.5.1 now reportedly accounts for one in seven cases in the United Kingdom.

The latest data from the Centers for Disease Control and Prevention (CDC) in the United States estimates the EG lineage - which includes EG.5.1 - now accounts for 17.3 per cent of the country's infections.

Adrian Esterman, a professor of biostatistics and epidemiology at the University of South Australia, said he expects a similar pattern will follow in Australia.

"Eris appears to have a bit of an advantage in terms of transmissibility, and it's starting to take over," he said.

"We'll probably see another peak of cases coming in the next few weeks, which will be due to Eris."

What are the symptoms of the new subvariant?

Symptoms of the EG.5.1 subvariant reportedly include a runny nose, headache, fatigue, sneezing and a sore throat.

Griffin says they appear to be relatively mild for most people.

"Some of that may be an impact of the vaccine, or past infection," he said.

"One of the main things people are talking about is it seems to be causing fever a little bit less commonly than some other variants and subvariants did previously."

Should you still be concerned about COVID-19?

According to the latest government data, 5,431 cases of COVID-19 were reported across Australia in the week to 2 August.

Griffin says because testing rates have declined, these numbers likely only represent a "fraction" of the cases in the community.

"I think for many people, COVID-19 is something that's certainly not forefront in their minds at the moment," he said.

"We've been through a fairly significant flu season recently and COVID numbers do seem to have declined in recent times, so I think for many people, they have lost sight of the significance of COVID."

He says while the pandemic is no longer considered a global health emergency, the threat has not gone away.

"If you look at the global figures, we've still had over a million cases in the last four weeks and over 3,000 deaths, so while the public health emergency has been declared over ... it's clear that the threat has not gone away," he said.

"Particularly as we see a new emerging subvariant, that may lead to an increase in cases in our country as it appears to be doing in others, so we need people to not completely lose sight of COVID."

For the elderly and those who have comorbidity factors, he suggests having a COVID-19 plan.

"That would include how to reduce your risk, whether through vaccine or other strategies, a plan for how to get tested quickly, how to get antivirals, and how to manage medical problems at those times," he said.

"Being prepared is going to be the main thing for the foreseeable future."