New Covid variant Eris is reminder to monitor virus data, US experts say

A new Covid-19 variant has become the dominant lineage of the virus in recent weeks in the US and while it should not be a cause of undue concern for the public, its emergence is a reminder of the need for greater surveillance of the virus and of the importance of vaccine boosters, according to infectious disease experts.

EG.5.1, an Omicron subvariant also known as Eris, is the leading version of the virus and makes up about 17% of Covid cases in the United States, according to the Centers for Disease Control and Prevention. Its rise coincides with a recent uptick in the number of hospitalizations due to Covid.

But those numbers remain far below hospitalization figures during the pandemic and do not indicate a need for social distancing measures or mask mandates, the experts said. The new variant is part of an anticipated evolution of the virus.

“As this virus continues to circulate, the potential for mutations to occur remains, and so we will see new genetic variants,” said Jennifer Nuzzo, an epidemiologist and director of the Pandemic Center at Brown University School of Public Health. “It’s very often the case when we see new genetic variants that they may increase in circulation. Sometimes they replace the variants that came before; sometimes they just kind of burn themselves out.”

Still, the exact scope of the virus is difficult to discern because of the limited surveillance measure, the experts said. Individuals, particularly those who are more vulnerable to the virus, should continue to monitor virus data. And people should also take a Covid test if they are sick.

“We do need to continue to keep our eye out and be cautious for something that is truly like a new pandemic strain,” which EG.5.1 is not, said Justin Lessler, an epidemiology professor at the University of North Carolina.

Joe Biden declared that the federal Covid public health emergency was over in April. That meant insurers no longer had to pay for over-the-counter tests and that people on Medicare would no longer receive free at-home test kits. Also, some people stockpiled tests during the pandemic, but many of those have expired.

“The biggest concern that we have right now is that testing is not nearly what it was in many, many countries,” including the United States, Nuzzo said.

As such, it’s more difficult to track virus trends and produce an accurate assessment of the virus.

Even if there is a high percentage of test positivity, it’s unclear whether it’s “because the only people getting tested right now are people who are really quite ill and know very well that they have Covid, versus maybe in the past people getting tested were people who needed a negative test before they could play sports or go to camp”, Nuzzo said. That “meant that we were sampling a larger portion of the population”.

Instead, public health agencies rely on wastewater testing, which allows them to see the amount of Covid and what variants are in that concentration. But it’s harder for people collecting that data to determine whether that means people are getting sicker or whether a person who is infected is infecting more people on a per-person basis, Nuzzo said.

“We can’t link the wastewater data to people,” she said. “It’s totally anonymous.”

Still, she said, “if the variant is a problem, we will see it, but the question is: how early will we see it?”.

“I don’t think there is this hidden severe wave,” Nuzzo added.

Even though people don’t want to submit to regular tests the way some had to during the pandemic, Nuzzo advocates for targeted testing, such as among people at nursing homes. Also, as the fall virus season approaches – meaning a likely uptick in Covid, flu and RSV cases –it’s important for healthcare workers to conduct tests in places with inadequate healthcare infrastructure, such as rural areas and low-income communities, Nuzzo said.

There were about 9,000 Covid hospitalizations during the last week of July, which was a 28% increase from a month earlier, according to the CDC.

During the Omicron wave in January 2022, there were 150,000 Covid hospitalizations in one week.

It’s unclear whether the uptick in hospitalizations is related to the emergence of the new variant, Lessler said.

“We don’t know if there’s something about getting this variant versus getting another variant that would be correlated with higher hospitalization,” Lessler said.

Regardless, the experts encouraged older adults or people who are immunosuppressed to wear masks when in public indoor spaces.

“I don’t think any country is going to reimpose lockdowns, mask mandates or social distancing,” said Dr Monica Gandhi, an infectious disease specialist at the University of California, San Francisco.

It’s also important for people to get an updated vaccine booster shot, Lessler said. The CEO of Pfizer, which manufactures a vaccine, said recently he thinks the FDA will authorize a booster this month.

“it’s the best way to protect yourself, and it also is an effective way to reduce the impact of the virus altogether,” Lessler said.

As to the outlook for the virus, Lessler said it will “probably continue to be a fairly major threat to human health for the foreseeable future, and we need to manage that just like we do for diabetes or heart disease”.