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  • A new recombinant variant has been discovered in the U.K.
  • Recombinant means it’s a mix of two strains.
  • Currently, BA.2 variant is the most common COVID-19 variant in the U.S.

In late March, the U.K. Health Security Agency (UKHSA) announced a new COVID-19 variant called XE.

According to the agency, this new variant is recombinant, meaning it’s a mix of two strains. In this case, highly infectious Omicron BA.1 has combined with the more recent BA.2 variant.

“A total 637 cases of XE – a recombinant of Omicron BA.1 and BA.2 – have been confirmed in the U.K. so far,” reported the UKHSA in late March. “The earliest of these has a specimen date of 19 January 2022.”

As viruses mutate over time, recombinant variants are likely to occur.

“It’s already happened a few times, and usually the way that it happens is you have two circulating variants, someone may get infected with both at the same time, and then the virus will recombine with characteristics of both variants,” Carlos Malvestutto, MD, an infectious disease specialist at the Ohio State University Wexner Medical Center, told Healthline.

Malvestutto confirmed that so far, there’s no indication that the XE variant is any better at escaping immunity gained by either prior infection or vaccination.

“We don’t really see in these few cases that have been seen in the U.K., China, India; we don’t see that it’s causing severe disease,” he continued.

One major question is whether this recombinant variant is more transmissible than other COVID-19 variants.

“It looks like the World Health Organization is citing estimates that show the XE is 10 percent more transmissible than the BA.2,” said Robert G. Lahita, MD, Director of the Institute for Autoimmune and Rheumatic Disease at Saint Joseph Health and author of Immunity Strong.

This comes as Omicron COVID-19 variant BA.2 has led to cases rising in the U.S. The variant makes up 72 percent of COVID-19 cases, according to the Centers for Disease Control and Prevention (CDC).

BA.2 cases were just shy of 14 percent at the beginning of March, and the agency warns they expect new COVID-19 variants to continue emerging.

As variants emerge, they may impact how effective current treatments are against COVID-19.

Malvestutto said he doubts that we’ll see reduced efficacy of currently approved monoclonal antibody treatments because XE should still have characteristics of other Omicron types.

“Several times we’ve had to change monoclonal antibodies that worked against previous variants that did not work against more recent ones,” he said. “Now the only ones that we’re using – one called sotrovimab, which worked fine against Omicron BA.1, but the neutralization activity of sotrovimab is not good against the BA.2 subvariant.”

He said that’s why they’ve switched to bebtelovimab, which is effective against BA.2.

“It’s not clear at this point if there would be reduced activity of bebtelovimab, nothing I’ve seen suggests that at this point, but we’re still waiting to see,” continued Malvestutto.

Lahita says he expects that we will likely see new COVID-19 variants emerge, “just like the flu.”

He also said he expects that should the disease become endemic; healthcare providers will end up giving vaccines for both influenza and COVID.

“And they will both, including influenza, be messenger RNA based,” he predicted.

He also predicts we’ll eventually rely on vaccines with mRNA from influenza and from all the COVID variants.

Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the University of Cincinnati College of Medicine, said a virus’ contagiousness doesn’t indicate how dangerous it might be.

“It just means that in animal models and humans, the rate of infection is higher,” he explained. “It does not mean it makes you sicker or more likely to be hospitalized.”

However, he cautioned that it’s too early to know if the XE variant will dominate over the current B.A.2 Omicron variant, which is very well adapted.

“[We] need more time to see if it will become predominant strain,” he said.

A new, more infectious COVID-19 variant called XE has been identified that has combined genetic information from both BA.1 and BA.2 variants. In early research, it appears to be more infectious than the Omicron BA.2 variant.

Experts say that increased infectiousness doesn’t mean it’s more dangerous and that current treatments will likely remain effective.