What to know about the new COVID-19 variant EG.5

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The new COVID-19 variant EG.5 has become the dominant strain in the United States and is making its way to Canada. The fast-spreading variant, first detected in February, has been behind upticks in the coronavirus across North America, and also has been detected in China, South Korea and Japan, among other countries.

On August 9, the World Health Organization classified EG.5 as a “variant of interest,” but said it did not seem to pose more of a threat to public health than others: “Collectively, available evidence does not suggest that EG.5 has additional public health risks relative to the other currently circulating Omicron descendent lineages,” the WHO said in a risk evaluation.

Here’s what is known about the emerging variant so far.

What is the new EG.5 COVID variant?

The EG.5 variant is a descendent lineage of XBB.1.9.2 – with one extra spike mutation – which is a descendent of Omicron. It was first reported on Feb. 17, 2023, and was designated as a variant under monitoring by WHO on July 19. The agency has since upgraded its classification of EG.5 to a variant of interest, putting it alongside XBB.1.5 and XBB.1.16, which are also a part of the Omicron family of strains.

It has been nicknamed “Eris” on social media by experts and scientists, to follow the Greek name classification of other variants, but the name is not officially used by WHO.

Which symptoms are associated with EG.5?

Officials say that symptoms of the EG.5 have been consistent with general COVID-19 symptoms, which include sore throat, fever or chills, runny nose, shortness of breath, muscle or body aches, headaches or new loss of smell or taste.

Dr. Angela Rasmussen, a virologist at the University of Saskatchewan’s Vaccine and Infectious Disease Organization, said the symptoms of EG.5 are similar to all other Omicron subvariants. “In vaccinated people who are not already at higher risk due to age or co-morbidities, it will generally be less severe than prior variants of concern like Alpha and Delta,” Dr. Rasmussen said.

According to an initial evaluation released by WHO on Wednesday, the public health risk by EG.5 is still determined as “low” at a global level and aligns with the risk of XBB.1.16 and other circulating variants. The report outlines that “there are no reported changes in disease severity to date” despite the increased prevalence of EG.5.

According to Dr. Fiona Brinkman, a professor at Simon Fraser University and member of the CoVaRR-Net’s CAMEO team, EG.5 is growing but “it’s not growing like gangbusters.”

“There are no alarm bells. That said, I do note that in all regions of the world mutations of EG.5 are growing consistently in prevalence,” Dr. Brinkman said.

Where is EG.5 being reported?

EG.5 has been reported in the United States, United Kingdom, India, China, Japan, South Korea and Canada. Globally, there has been a steady increase in the number of EG.5 cases reported. The variant accounted for 17.4 per cent of weekly cases from July 17 to 23 – up from 7.6 per cent during the week of June 19 to 25.

In the United States, EG.5 is already the most common subvariant. According to the Center for Disease Control and Prevention, EG.5 accounts for around 17.3 per cent of all COVID-19 cases in a two-week period ending August 5.

The EG.5 subvariant has been circulating in Canada since May, according to the Public Health Agency of Canada. PHAC estimates suggest that EG.5.1, the most prevalent EG.5 lineage, made up 19 per cent of cases in Canada between July 30 and August 5. A second EG.5 lineage, EG.5.1.1, made up 17 per cent of cases in the same time period.

The agency also said that EG.5 has been detected 36 times in municipal wastewater between May 15 and July 21.

The lack of widespread general public testing in Canada makes it difficult to know exactly how many cases of EG.5 there are currently. But according to sequencing by Public Health Ontario, XBB.1.5 is still the most prevalent subvariant in that province, while the proportion of EG.5 is increasing. Of the 245 samples sequenced between July 9 to July 15, EG.5 accounted for 12.7 per cent, an increase from 5.2 per cent the previous week. The agency expected that number to increase to 30.5 per cent by August 5.

Dr. Nazeem Muhajarine, an epidemiology professor at the University of Saskatchewan and co-lead of the public health and social policy impacts section of the Coronavirus Variants Rapid Response Network, said although we’re seeing upticks in positivity rates, it’s not yet known how dangerous the new subvariant could be.

“We haven’t yet seen in a clear way these increases in cases converting to hospitalizations and deaths attributed to EG.5. We have to be careful about making attribution of hospitalizations and deaths to this particular subvariant just yet,” Dr. Muhajarine said.

Dr. Rasmussen also said the risk profile of the new subvariant is similar to prior Omicron subvariants: “While EG.5 is likely to have a transmission advantage over XBB subvariants - that’s how it would outcompete them - there is no data suggesting it causes more severe disease.”

Will the new boosters work against EG.5?

The National Advisory Committee on Immunization is recommending Canadians who have gone more than six months without a COVID-19 shot or infection should get a booster with a new formulation of the vaccine this fall.

Dr. Muhajarine said the fall boosters are monovalent COVID-19 vaccines, meaning they target Omicron variants. “Since EG.5 is a offshoot of Omicron subvariant, these booster doses would be effective against it.”

What is the state of COVID-19 in Canada? And what can Canadians expect this fall?

According to a British Medical Journal report released in July, COVID-19 has led to 52,750 deaths and 4.6 million reported cases (as of mid-2023) in Canada since the beginning of the pandemic. The report found that marginalized communities were hit the hardest, along with individuals working and living in long-term care homes. The death rate in Canada’s LTC homes was, proportionally, the worst in the world.

Canada’s COVID-19 death rate, 1,372 per million population, was worse than the global average of 855, but markedly better than the 3,332 per million deaths in the U.S. and 3,362 in the U.K.

WHO director general Tedros Adhanom Ghebreyesus ended the global emergency status, the WHO’s highest level of alarm, for COVID-19 in May.

Dr. Muhajarine said it’s likely Canada will see a bump in COVID-19 cases and hospitalizations in the fall. “Our collective immunity, from both having COVID and getting vaccines, are not constant yet, and will be changing, meaning decreasing.”

Dr. Rasmussen recommends a few ways Canadians can continue to protect themselves during the fall:

• Ensure you are up-to-date on vaccines, including boosters if recommended. “The XBB-specific boosters expected in the fall should still provide protection against EG.5, since it is derived from the XBB lineage.”
• Consider layering on other protections: wearing masks in higher risk situations (indoors, especially in crowded environments or while traveling), installing HEPA air filtration or Corsi boxes, and testing.
• Stay home when you aren’t feeling well and keep children home from school when they are sick, which “also helps reduce the spread of other seasonal infections, like colds and the flu.”
• Get the seasonal flu shot.

With reports from Kelly Grant, André Picard and Reuters