This new COVID-19 strain is set to hit the US

An emergent COVID-19 variant, XEC, is spreading across the globe.^[] The variant is a blend of the KP.3.3 and KS.1.1. variants. Cases are mostly being reported across Europe, having first appeared in Italy in May and been formally identified in Berlin in August. 

In Europe, XEC has made up about 8% of all cases this month, double that of last month’s case numbers. It’s most widespread in France, making up around 21% of all tracked cases. 

The good news? “It is not emergent in the United States,” David Cutler, MD, a board-certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, says. Currently, sources say that, as of mid-September, XEC comprises just about 1% of COVID-19 cases in the US.^[] For context, it doesn’t even have its own spot on the Centers for Disease Control and Prevention’s  COVID-19 data tracker.^[]

KP.3.3 is an offshoot of the KP.3 Omicron variant family, which was surging in the US this summer.^[] These variants, including XEC, share many of the same qualities as other Omicron variants,  meaning they are easily transmittable but less severe than, say, earlier pandemic strains. ^[][] Some variants, like this one, Dr. Cutler says, “tend to be more infectious but not more severe because [the variant] wants to let the host live in order to spread the virus.”

Mark Cameron, PhD, Associate Professor in the Department of Population and Quantitative Health Sciences at Case Western Reserve University, tells MDLinx that the XEC variant may just have the power to drive infections through the fall and winter. “But we need to know more about the XEC variant, and perhaps those still to come. As yet another Omicron family member, being up to date on the latest COVID-19 boost is a protective measure we can take right now,” he says.

Scott Roberts, Assistant Professor of Infectious Diseases at Yale School of Medicine, explains that the increase in transmission is “likely due to XEC bypassing some of our immune defenses, as it is somewhat distinct from current variants. But this is no different from any other novel variant we have seen in the past few years.”

Dr. Roberts explains that since XEC is a recombinant strain of two Omicron strains, the current vaccines should provide protection against it—although, with time, we will know more.

Beyond getting vaccinated, patients should also know the risks associated with long COVID. “Long COVID risk with XEC is likely to be the same as any other variant,” Dr. Roberts adds. “Note that even mild cases of COVID can lead to long COVID, and vaccination is the best weapon we have against long COVID. Other strategies have not panned out, but the vaccine has.”

Even though we are currently living in the “new normal,” Dr. Cutler says, the US has still seen between 500 and 1,000 people die from COVID-19 within the past month.^[] For this reason, patients have to identify their risk level and act accordingly in order to protect themselves. 

Amy Edwards, MD, Associate Professor in the Department of Pediatrics at the Case Western Reserve University School of Medicine, tells MDLinx that patients should continue to protect themselves from the virus, especially going into the cooler months when viruses tend to proliferate. “Wash your hands, get your COVID-19 shot, stay home when you are ill, and wear a mask if you are feeling unwell but not sick enough to stay home,” she says. “Avoid crowded, poorly ventilated events. If you want to wear a mask for protection, it needs to be a very well-fitted N95.”