A new sub-variant of Covid has been dubbed "Eris." Photo: 123rf.com / Composite Image - RNZ
By Smitha Mundasad for the BBC w/RNZ
The World Health Organization has declared a new sub-variant of Covid called EG.5 - unofficially named "Eris" - a variant of interest and is asking countries to monitor it as cases grow globally.
But the organisation says it poses a low risk to public health, with no evidence that it causes more severe disease than other variants circulating at the moment.
A New Zealand epidemiologist said the new Covid-19 variant is not cause for particular concern but does show the virus is continuing to evolve.
EG.5 has become the dominant variant in the United States.
It has already been found in New Zealand, according to the Institute of Environmental Science and Research (ESR) report released 4 August, which said it was "gradually increasing, but not at a rate that would cause a substantial surge in new cases."
XBB remains the most prominent variant here.
Epidemiologist Michael Baker said new variants and sub-variants can be expected.
"Any new variant or sub-variant that gets an edge will start to take over from those that came before, and that edge comes from the fact that it can escape some of our immunity.
"So it's natural selection, operating before our eyes."
Officials are looking at EG.5's impact overseas, he said.
"What we have seen overseas since this new variant emerged is it appears to have caused a slight rise of cases in the US and Europe. That would be one impact we might see in New Zealand.
"We're not seeing that impact at this stage, because we're actually at the lowest point we've been to since Omicron arrived in New Zealand."
Baker said the new variant is not cause for particular concern but does show the virus is continuing to evolve.
"It just reminds us that this virus is not staying still. It's continuing to evolve.
"And in the future we could well see a bigger jump in its evolution that does have a significant effect on case numbers and it does mean that we really do need to revise our vaccines, for example."
Epidemiologist, Professor Michael Baker. Photo: RNZ / Samuel Rillstone
What is EG.5 and why has it been dubbed Eris?
Ever since it first emerged, Covid has been mutating or shape-shifting and becoming incrementally different. The new genetic versions that keep appearing are called variants.
EG.5 is another off-shoot of the Omicron variant of Covid. According to the WHO, it was first seen in February 2023 and cases have been increasing steadily.
It has been dubbed Eris on social media - also the name of a goddess in Greek mythology.
The unofficial nickname may follow on from the WHO convention of using letters of the Greek alphabet to assign, "simple, easy-to-say labels" for key variants.
The WHO naming system arose after experts agreed scientific names were difficult to remember and prone to misreporting. It was also intended to stop variants being named after the countries they were first spotted in.
In its latest assessment, the WHO includes EG.5 and sub-variants very closely related to it, including 5G.5.1.
According to the UK Health Security Agency (UKHSA), 5G.5.1 now makes up about one in seven cases of Covid picked up by hospital tests.
Dr Meera Chand, the agency's deputy director, said "it was not unexpected" to see new variants emerge.
She continued: "EG.5.1 was designated as a variant on 31 July 2023 due to continued growth internationally and presence in the UK, allowing us to monitor it through our routine surveillance processes."
Cases of EG.5 are also rising in the US, where it has narrowly surpassed other circulating omicron sub-variants, according to estimates published by the US Centers for Disease Control and Prevention.
Is Eris more dangerous?
Based on the available evidence, WHO officials say there is no suggestion the sub-variant is causing more severe disease and the risks are no higher than other current variants of interest.
Some tests suggest it can evade our immune systems more easily than some circulating variants but this has not been translated into people becoming more seriously ill.
In the UK, there has been a small increase in people in hospital in recent weeks, particularly those aged over 85, but experts say the numbers remain lower than previous waves. There has been no increase in people severely unwell in intensive care.
Experts around the world will continue to monitor the sub-variant and assess its impact, particularly as schools and universities reopen.
A healthcare worker member draws up a syringe with the BioNTech, Pfizer vaccine adapted to the Omicron-BA.1 variant. Photo: Sebastian Gollnow / DPA / dpa Picture-Alliance via AFP
Where is EG.5 spreading?
According to the WHO, infections have been reported in 51 countries as of 7 August, including China, the US, the Republic of Korea, Japan, Canada, Australia, Singapore, the UK, France, Portugal and Spain.
What are the symptoms?
Experts say there is no evidence to suggest it causes any new Covid symptoms.
Have I got Covid, a bad cold or something else?
Symptoms of Covid can include:
- fever
- continuous cough
- change in sense of taste or smell
- fatigue
- runny nose
- sore throat
How can you protect yourself?
As with other Covid variants, the risk of serious illness remains highest for people who are elderly or have significant underlying health conditions.
Health officials say vaccination remains the "best defence against future Covid waves, so it is still as important as ever that people take up all the doses for which they are eligible as soon as possible".
The WHO says it continues to assess the impact of variants on the performance of vaccines to inform decisions on updates to vaccine composition.
Health experts recommend regular handwashing and staying away from others where possible if you have symptoms of a respiratory illness.
More New Zealand Covid-19 vaccination information can be found here.
* Much of this story was first published by the BBC, with RNZ reporting added to include New Zealand information.