A new strain of Covid-19 has been designated as a variant of interest by the World Health Organization, although the public health risk has been judged as low.
The variant, known as EG.5 or “Eris”, is related to an Omicron subvariant called XBB.1.9.2, and is growing in prevalence globally, with countries including the UK, China and US among those affected.
However, the WHO suggested the variant does not pose a particular threat. “Based on the available evidence, the public health risk posed by EG.5 is evaluated as low at the global level,” the agency said, adding that the risk appeared to be on a par with other circulating variants of interest.
“While EG.5 has shown increased prevalence, growth advantage, and immune escape properties, there have been no reported changes in disease severity to date,” the WHO added.
Christina Pagel, professor of operational research at University College London, said that while the variant was growing in prevalence and appeared to be better at evading the immune system, allowing it to outcompete other variants, there was no evidence that it caused more severe disease.
“It will probably cause a wave of more cases and all the problems that brings – [such as] more hospitalisations and Long Covid– but [there is] no reason at the moment to think [that will be] worse than previous waves this year,” she said.
Pagel noted that waning immunity whether from vaccinations or previous infections may mean the wave of EG.5 took longer to peak and hence could be larger.
Prof Stephen Griffin, a virologist at the University of Leeds, said that while the prevalence of the variant was increasing relatively slowly in the UK, its infectiousness and ability to evade antibodies meant that the number of cases could grow more rapidly when schools return and people go back to work and university after the summer.
Prof John Edmunds, an infectious diseases expert at the London School of Hygiene & Tropical Medicine, said the new variant may well cause an increase in incidence, but added: “Successive waves of Omicron sub-variants has been the pattern for the last 18 months now.”
The WHO listed a number of actions it recommended member states prioritise to better understand antibody escape and severity of EG.5, including monitoring for changes in indicators of severity.
Last week, the UK Health Security Agency (UKHSA) published an update that suggested EG.5, or more specifically its subvariant EG5.1, accounts for an estimated 15% of sequenced Covid-19 cases in England.
Dr Meera Chand, the deputy director of UKHSA, said the emergence of new variants was not unexpected.
“UKHSA continues to analyse available data relating to Sars-CoV-2 variants in the UK and abroad,” she said. “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.”
Chand added: “Vaccination remains our best defence against future Covid-19 waves, so it is still as important as ever that people come take up all the doses for which they are eligible as soon as possible.”
