New COVID Variant XEC Spreads to Half of U.S. States: What to Know

• The XEC coronavirus variant is quickly driving up case counts in Europe and could soon become predominant in the United States, experts say.
• The variant has mutations that make it highly contagious, but health authorities doubt it will lead to an increase in severe illness.
• The updated 2024–2025 COVID-19 vaccines are expected to provide strong protection against XEC.

As the summer COVID surge driven by the so-called FLiRT variants finally appears to be subsiding, American health authorities fear a new variant called XEC — which is swiftly spreading through Europe — may help drive another wave of illness in the United States, reports Everday Health.

XEC

This latest coronavirus variant has shown strong growth in Denmark, Germany, the United Kingdom, and the Netherlands, according to the global science initiative GISAID.org.  Another source of information on COVID variants, Outbreak.info, reports that scientists have detected XEC in at least 28 countries, including Australia, China, and South Korea.

Illnesses traced to XEC are still too limited in the United States to appear on tracking charts shared by the Centers for Disease Control and Prevention (CDC), making up fewer than 1 percent of cases, but surveillance teams have identified a small number of sicknesses in numerous states — Arizona, California, Colorado, Delaware, Florida, Hawaii, Illinois, Iowa, Maryland, Massachusetts, Michigan, Nebraska, Nevada, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, South Dakota, Texas, Utah, Virginia, and Washington.

How Is XEC Different From the Current Top Variants?

Right now, the coronavirus variant KP3.1.1 (a close relative of other top variants — KP.2, KP.2.3, and KP.3) accounts for about half of the COVID-19 infections in the country.

XEC is different, though, because it is a “recombinant” virus, meaning it incorporates features from two other variants (in this case, KS.1.1 and KP.3.3), explains Peter Chin-Hong, MD, a professor of medicine at the University of California in San Francisco, who specializes in infectious diseases.

He points out that XEC has a mutation in a so-called spike protein that may improve its ability to bind to human cells, which in turn may heighten contagiousness.

Eric Topol, MD, director of the Scripps Research Translational Institute, recently posted on X (formerly Twitter) that the XEC variant has “the most growth advantage of any circulating [variant].”

Will Vaccines Offer Enough Protection?

Dr. Chin-Hong advises the public to be “curious and vigilant” but not overly worried about XEC: The variant, he says, doesn’t appear to pose a greater health threat than other currently circulating variants.

Although the updated 2024–2025 COVID vaccine was formulated specifically to protect against variants from the recent past, XEC is closely related to those variants, so the vaccine is expected to be effective against XEC as well, according to Chin-Hong.

This is why Chin-Hong and other healthcare providers are emphasizing the importance of vaccination — especially for people who are particularly vulnerable to severe COVID-19 like the elderly or the very immunocompromised. In these groups, immunity from earlier vaccinations or infections will likely have sufficiently worn off by now.

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