A novel coronavirus (SARS-CoV-2) variant known as EG.5.1 is spreading around the world, health experts have said.

As of July 24, 2,442 sequences of EG.5.1 had been detected in 36 countries around the world, including at least 18 cases in Israel, according to data from Outbreak.info, a site that aggregates data about SARS-CoV-2.

The strain has become more prevalent in the UK as COVID-19 hospitalizations continue to rise, British health officials said on Thursday. On social media, virologists have nicknamed the variant “Eris.”

According to the UK Health Security Agency (UKHSA), monitoring of the EG.5.1 variant began in early July due to increasing reports of the variant internationally, especially in Asia. The variant was first detected in March.

An update from the UKHSA on Wednesday showed that cases of the EG.5.1 and XBB.1.16 (also known as Arcturus) variants were rising. 

In the week beginning July 10, 11.8% of genetically sequenced cases of the novel coronavirus were found to be EG.5.1. As of July 20, that percentage had increased to 14.55% of all cases.

A relative of the variant, EG.5, was marked as a variant for monitoring by the World Health Organization in July. According to the WHO, that variant was first detected in February.

According to Meaghan Kall, an epidemiologist at the UKHSA, EG.5.1 accounts for 20% of sequenced cases in Asia, 10% of sequenced cases in Europe and 7% of sequenced cases in North America. Kall noted that past variants with similar growth advantage rates have not sparked new waves of infections.

The rise in EG.5.1 cases comes as the UK reports an increase in COVID-19 hospitalizations as well.

“We continue to see a rise in COVID-19 cases in this week’s report. We have also seen a small rise in hospital admission rates in most age groups, particularly among the elderly,” said Dr. Mary Ramsay, head of Immunization at the UKHSA. “Overall levels of admission still remain extremely low and we are not currently seeing a similar increase in ICU admissions. We will continue to monitor these rates closely.”

“The NHS will be in contact in autumn 2023 when the seasonal vaccine is available for those who are eligible due to health conditions or age, and we urge everyone who is offered to take up the vaccine when offered.”

Coronavirus cases rising around the globe

Increases in coronavirus cases have been reported in other countries as well recently.

In Japan, cases have been rising for 17 weeks straight, with the country’s Health Ministry stating on Friday that 78,502 cases were reported in the seven-day period ending on July 30, an increase of 9,901 cases from the week before. Hospitalizations rose by 14% as well in that period.

In the US, EG.5 is the leading variant, making up 17.3% of cases in the country, followed by XBB.1.16 which makes up 15.6% of the cases, according to US Centers for Disease Control and Prevention (CDC) data from Saturday.

Hospitalization rates due to COVID-19 have risen in recent weeks in the US as well. CDC data shows an upward tick in hospitalizations, with 8,035 hospitalizations due to the virus during the week of July 22, compared to 7,165 hospitalizations the week before.

Scientists warn decreased surveillance making it harder to track new variants

As we near the Fall, scientists have expressed concerns that the decrease in testing and sequencing occurring across the globe will make it harder to monitor new variants.

Christina Pagel, a professor of operational research at University College London, told The Guardian on Saturday that she would call for monitoring practices, including wastewater monitoring, to be increased again ahead of the Fall.

“What worries me most is if we get a repeat of the last winter NHS crisis this winter again, with Covid, flu and RSV all hitting around the same time,” said Pagel. “We are definitely flying near blind.”

Ulrich Elling, a research group leader at the Austrian Academy of Sciences’ Institute of Molecular Biotechnology, called the rate of sequencing around the world “a disgrace” in a tweet on Twitter, noting that only 50 cases were sequenced in Africa, 7.7 thousand were sequenced in Asia, 2.8 thousand were sequenced in Europe, 7.1 thousand were sequenced in North America, and 1,000 were sequenced in Oceania.

“Should we really call that surveillance? How are we supposed to call out relevant variants early? How should we prepare suited vaccinations in time? How should we model epicurves?” added Elling. “The variant "Eris" EG.5.1, a daughter of XBB.1.9.2 with F456L and Q52H, is growing in Europe and worldwide. Together with weaning immunity after a calm northern hemisphere summer, the immanent onset of fall, and school openings we will see significantly more infections.”

On Wednesday, Maria Van Kerkhove, the technical lead for the COVID-19 response at the WHO, urged member states to “maintain, not dismantle, established COVID-19 infrastructure: sustain surveillance & reporting, variant tracking, early clinical care provision, vaccine boosters to high-risk groups, ventilation improvements, communication, etc.”