Hybrid COVID variant XEC is more contagious: What to know about the new strain
The side effects of newly discovered COVID-19 strain XEC might not be as severe, but is part of the more contagious variant class, experts say.
The Centers for Disease Control and Prevention (CDC) defines XEC as recombinant or hybrid of the strains KS.1.1 and KP.3.3., both from the Omicron family that became the predominant strain in the U.S. late December 2022.
The variant, which first appeared in Berlin in late June, has increasingly seen hundreds of cases in Germany, France, Denmark and Netherlands, according to a report by Australia-based data integration specialist Mike Honey.
XEC has also been reported in at least 25 U.S. states though there could be more as genetic testing is not done on every positive test, RTI International epidemiologist Jo?lla W. Adams said.
"We often use what happens in Europe as a good indication of what might happen here," Adams told USA TODAY Friday. "Whenever we're entering into a season where we have multiple viruses occurring at the same time, like we're entering into flu season, that obviously complicates things."
What is the XEC variant?
New COVID strain XEC is a recombinant strain of two variants in the Omicron family: KS.1.1 and KP.3.3.
The hybrid strain was first reported in Berlin late June but has spread across Europe, North America and Asia with the countries Germany, France, the Netherlands and Denmark leading cases.
Is the XEC variant more contagious?
While there's no indication the XEC strain will increase the severity of virus, it could potentially become a dominant strain as Omicron variants are more contagious. However, current available COVID-19 vaccines and booster shots are particularly protective against XEC as it is a hybrid of two Omicron strains.
"These strains do have the advantage in the fact that they are more transmissible compared to other families, and so the vaccines that are currently being offered were not based off of the XEC variant, but they are related," Adams said.
Like other respiratory infections, COVID-19 and its recent Omicron variants will increasingly spread during the fall and winter seasons as students return to classes, kids spend more time inside and people visit family for the holidays, according to Adams.
How can we protect ourselves from XEC and other variants?
The CDC continues to monitor the emergence of variants in the population, according to spokesperson Rosa Norman.
"At this time, we anticipate that COVID-19 treatments and vaccines will continue to work against all circulating variants," Norman said in a statement to USA TODAY. "CDC will continue to monitor the effectiveness of treatment and vaccines against circulating variants."
The CDC recommends that everyone ages 6 months and older, with some exceptions, receive an updated 2024-2025 COVID-19 vaccine to protect against the virus, regardless whether or not you have previously been vaccinated or infected.
Norman urged Americans to monitor the agency's COVID Data Tracker for updates to new variants.
KP.3.1.1: This dominant COVID-19 variant accounts for over 50% of cases, new CDC data shows
What is the dominant strain of COVID in the US?
COVID-19 variant KP.3.1.1 is currently the dominant strain accounting for more than half of positive infections in the U.S. according to recent CDC projections.
Between Sept. 1 and Sept. 14, 52.7% of positive infections were of the KP.3.1.1 strain, followed by KP.2.3 at 12.2%, according to the agency's Nowcast data tracker, which displays COVID-19 estimates and projections for two-week periods.
KP.3.1.1 first became the dominant strain in the two-week period, starting on July 21st and ending on August 3rd.
"The KP.3.1.1 variant is very similar to other circulating variants in the United States. All current lineages are descendants of JN.1, which emerged in late 2023," Norman previously told USA TODAY.
COVID XEC symptoms
There is no indication that the XEC variant comes with its own unique symptoms.
The CDC continues to outline the basic COVID-19 symptoms, which can appear between two to 14 days after exposure to the virus and can range from mild to severe.
These are some of the symptoms of COVID-19:
Fever or chills
Cough
Shortness of breath or difficulty breathing
Fatigue
Muscle or body aches
Headache
Loss of taste or smell
Sore throat
Congestion or runny nose
Nausea or vomiting
Diarrhea
The CDC said you should seek medical attention if you have the following symptoms:
Trouble breathing
Persistent pain or pressure in the chest
New confusion
Inability to wake or stay awake
Pale, gray or blue-colored skin, lips, or nail beds
Contributing: Ahjane? Forbes
This article originally appeared on USA TODAY: COVID variant XEC, more contagious, could become dominant strain in US
