The SARS-CoV-2 virus, which causes COVID-19, continues to mutate, leading to new and highly contagious variants. The latest variant gaining attention is XEC, a recombinant omicron variant, which has recently sparked discussions among scientists on X.
.jpeg)
Dr. Eric Topol, a physician-scientist and director of the Scripps Research Translational Institute, posted on X last week that the 'XEC variant appears to be the most likely one to take hold next.
As respiratory virus season nears in the U.S., there are concerns about whether the XEC variant could trigger a fall surge and whether the new COVID-19 vaccines will protect against it.
What do we know about the XEC variant so far? What symptoms does it cause, and what can we expect in the coming months?
"What is the XEC COVID-19 variant?"
As respiratory virus season nears in the U.S., there are concerns about whether the XEC variant could trigger a fall surge and whether the new COVID-19 vaccines will protect against it.
What do we know about the XEC variant so far? What symptoms does it cause, and what can we expect in the coming months?
"What is the XEC COVID-19 variant?"
.jpeg)
XEC is a recombinant variant formed from two previous strains, KP.3.3 (a FLiRT variant) and KS.1.1, explains Dr. Albert Ko, an infectious disease physician and professor at Yale School of Public Health.
'When a person is infected with two different SARS-CoV-2 variants, recombination can occur, where pieces of genetic material from one variant merge with the other, creating a new strain,' Ko says.
The XEC variant is a sublineage of omicron, similar to the recent variants circulating in the past few months, notes Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center.
These include the FLiRT strains and the currently dominant variant in the U.S., KP.3.1.1, also known as 'DeFLuQE' by some scientists.
According to Mike Honey, an Australian data scientist tracking XEC’s spread, the variant first appeared in Berlin in late June and has since rapidly spread across Europe, North America, and Asia, as he noted in a Sept. 14 post on X.
XEC is showing the 'strongest growth' in Germany and Denmark, Honey added, and has been reported in at least 27 countries so far.
In the U.S., at least 95 cases have been reported across 12 states, according to the latest data from Scripps Research's COVID-19 database, Outbreak.info.
'It's definitely here, but it hasn’t yet appeared on the CDC tracker due to the low number of detected cases,' says Ko. XEC is not yet listed on the U.S. Centers for Disease Control and Prevention's 'Nowcast' estimates, which project COVID variant proportions for the most recent two-week period.
However, this could change. Honey mentioned that XEC 'looks like a likely next challenger to the currently dominant DeFLuQE variants,' in his Sept. 14 post on X.
"Is XEC more contagious?"
XEC seems to be quite contagious, like many of the recent Omicron variants, which is why it's gaining traction,” says Schaffner.
XEC, like other COVID variants, spreads from person to person through respiratory droplets produced when an infected individual breathes, talks, coughs, or sneezes.
“It’s currently rising at a fast rate and is the fastest-growing variant in a few European countries,” says Andrew Pekosz, PhD, professor and vice chair of the Department of Molecular Microbiology and Immunology at Johns Hopkins Bloomberg School of Public Health.
“Whenever a new variant emerges and starts to increase rapidly, we pay close attention. That’s usually the first signal that something significant might be happening,” says Pekosz.
The XEC variant has at least one mutation in its spike protein, which may potentially increase its transmissibility, though it’s unclear if XEC will outcompete other variants.
“It seems to be behaving similarly to other Omicron subvariants so far. No major red flags have been raised regarding XEC,” says Schaffner.
"Will XEC cause a fall surge in the U.S.?"
The 2024 summer wave was more prominent and prolonged than expected. It’s only now starting to decline,” says Schaffner.
There is no specific COVID 'season' in the U.S., and activity can continue throughout the year. While cases often peak in the winter during respiratory virus season, they can also surge in the spring and summer, according to the CDC.
The timing and severity of COVID-19 surges are hard to predict, says Pekosz. He speculates that this winter’s wave might come later or be smaller than last year’s due to the size of the summer wave, which provided some immunity. However, it’s unclear how the next few months will unfold.
It’s also too early to determine whether XEC or another variant will drive a fall or winter surge. “New variants with new mutations emerge; some take off, and some don’t,” says Ko.
"XEC might be the next variant to take off and cause a wave, but we’re not sure how significant that wave will be," Ko adds.
One thing we do know is that respiratory virus season is approaching, and viruses like SARS-CoV-2 and influenza spread more easily in the winter when people gather indoors.
“I can confidently predict a winter increase. When and how severe that increase will be is uncertain, but this shouldn’t influence your decision to get vaccinated,” Schaffner adds.
"What are the symptoms of XEC?"
It's still early in XEC's emergence, so there isn't much information yet about its symptoms or other clinical features, says Pekosz. However, so far, XEC does not appear to cause any new or more severe symptoms.
"It’s the same as before," Schaffner adds. The symptoms of XEC are similar to those of previous omicron variants, including:
- Sore throat
- Cough
- Fatigue
- Headache and body aches
- Congestion
- Runny nose
- Fever or chills
- Shortness of breath
- Nausea or loss of appetite
- Diarrhea
- Loss of sense of taste or smell
It can make you feel miserable for several days, but symptoms can vary from person to person, and some people may have an asymptomatic infection," says Schaffner.
People in high-risk groups, such as those over 65, those with underlying conditions like diabetes or heart disease, and immunocompromised individuals, are more likely to develop severe illness.
“There’s nothing particularly concerning about XEC in terms of the symptoms it causes or its ability to lead to hospitalizations and deaths,” says Ko. So far, XEC seems similar to KP.2 and KP.3, he adds.
"Will the COVID vaccine protect against XEC?"
The updated COVID-19 vaccine for 2024–2025 is now available and recommended by the CDC for everyone aged six months and older.
The new mRNA vaccines are monovalent, targeting a single variant—specifically, the previously dominant KP.2 variant, says Pekosz. "XEC appears to be closely related to the vaccine strains, so there should be good coverage," he adds.
“Although it’s new, early lab studies suggest the updated vaccine will protect against severe disease caused by this variant,” Schaffner adds.
COVID-19 vaccines are safe and effective at preventing severe illness, hospitalization, and death, according to the CDC. This means they can still offer protection even if someone contracts COVID-19 after vaccination.
The strains targeted by the vaccines are selected over the summer, several months before the shots become available, Pekosz notes. "While the vaccine strain doesn't change, the virus continues to infect people and mutate, so we never have a perfect match," he adds.
However, it appears that the current vaccines will provide protection if the XEC variant spreads widely in the U.S. this fall.
"Now (through October) is a good time to get vaccinated," says Ko. If you’ve recently recovered from a COVID-19 infection, the CDC recommends waiting three months before getting the vaccine, but always consult your doctor.
It's especially important for those at higher risk of severe disease to get the updated COVID-19 vaccine, says Schaffner. High-risk individuals should get vaccinated as soon as possible because the virus is still circulating at relatively high levels nationwide, TODAY.com previously reported.
Experts are concerned that poor vaccine uptake could create a more vulnerable population this winter. "Last year, only 24% of the eligible population received the vaccine, so I hope we do much better this fall," says Schaffner.
"Testing and isolation guidelines"
'When a person is infected with two different SARS-CoV-2 variants, recombination can occur, where pieces of genetic material from one variant merge with the other, creating a new strain,' Ko says.
The XEC variant is a sublineage of omicron, similar to the recent variants circulating in the past few months, notes Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center.
These include the FLiRT strains and the currently dominant variant in the U.S., KP.3.1.1, also known as 'DeFLuQE' by some scientists.
According to Mike Honey, an Australian data scientist tracking XEC’s spread, the variant first appeared in Berlin in late June and has since rapidly spread across Europe, North America, and Asia, as he noted in a Sept. 14 post on X.
XEC is showing the 'strongest growth' in Germany and Denmark, Honey added, and has been reported in at least 27 countries so far.
In the U.S., at least 95 cases have been reported across 12 states, according to the latest data from Scripps Research's COVID-19 database, Outbreak.info.
'It's definitely here, but it hasn’t yet appeared on the CDC tracker due to the low number of detected cases,' says Ko. XEC is not yet listed on the U.S. Centers for Disease Control and Prevention's 'Nowcast' estimates, which project COVID variant proportions for the most recent two-week period.
However, this could change. Honey mentioned that XEC 'looks like a likely next challenger to the currently dominant DeFLuQE variants,' in his Sept. 14 post on X.
"Is XEC more contagious?"
XEC seems to be quite contagious, like many of the recent Omicron variants, which is why it's gaining traction,” says Schaffner.
XEC, like other COVID variants, spreads from person to person through respiratory droplets produced when an infected individual breathes, talks, coughs, or sneezes.
“It’s currently rising at a fast rate and is the fastest-growing variant in a few European countries,” says Andrew Pekosz, PhD, professor and vice chair of the Department of Molecular Microbiology and Immunology at Johns Hopkins Bloomberg School of Public Health.
“Whenever a new variant emerges and starts to increase rapidly, we pay close attention. That’s usually the first signal that something significant might be happening,” says Pekosz.
The XEC variant has at least one mutation in its spike protein, which may potentially increase its transmissibility, though it’s unclear if XEC will outcompete other variants.
“It seems to be behaving similarly to other Omicron subvariants so far. No major red flags have been raised regarding XEC,” says Schaffner.
"Will XEC cause a fall surge in the U.S.?"
The 2024 summer wave was more prominent and prolonged than expected. It’s only now starting to decline,” says Schaffner.
There is no specific COVID 'season' in the U.S., and activity can continue throughout the year. While cases often peak in the winter during respiratory virus season, they can also surge in the spring and summer, according to the CDC.
The timing and severity of COVID-19 surges are hard to predict, says Pekosz. He speculates that this winter’s wave might come later or be smaller than last year’s due to the size of the summer wave, which provided some immunity. However, it’s unclear how the next few months will unfold.
It’s also too early to determine whether XEC or another variant will drive a fall or winter surge. “New variants with new mutations emerge; some take off, and some don’t,” says Ko.
"XEC might be the next variant to take off and cause a wave, but we’re not sure how significant that wave will be," Ko adds.
One thing we do know is that respiratory virus season is approaching, and viruses like SARS-CoV-2 and influenza spread more easily in the winter when people gather indoors.
“I can confidently predict a winter increase. When and how severe that increase will be is uncertain, but this shouldn’t influence your decision to get vaccinated,” Schaffner adds.
"What are the symptoms of XEC?"
It's still early in XEC's emergence, so there isn't much information yet about its symptoms or other clinical features, says Pekosz. However, so far, XEC does not appear to cause any new or more severe symptoms.
"It’s the same as before," Schaffner adds. The symptoms of XEC are similar to those of previous omicron variants, including:
- Sore throat
- Cough
- Fatigue
- Headache and body aches
- Congestion
- Runny nose
- Fever or chills
- Shortness of breath
- Nausea or loss of appetite
- Diarrhea
- Loss of sense of taste or smell
It can make you feel miserable for several days, but symptoms can vary from person to person, and some people may have an asymptomatic infection," says Schaffner.
People in high-risk groups, such as those over 65, those with underlying conditions like diabetes or heart disease, and immunocompromised individuals, are more likely to develop severe illness.
“There’s nothing particularly concerning about XEC in terms of the symptoms it causes or its ability to lead to hospitalizations and deaths,” says Ko. So far, XEC seems similar to KP.2 and KP.3, he adds.
"Will the COVID vaccine protect against XEC?"
The updated COVID-19 vaccine for 2024–2025 is now available and recommended by the CDC for everyone aged six months and older.
The new mRNA vaccines are monovalent, targeting a single variant—specifically, the previously dominant KP.2 variant, says Pekosz. "XEC appears to be closely related to the vaccine strains, so there should be good coverage," he adds.
“Although it’s new, early lab studies suggest the updated vaccine will protect against severe disease caused by this variant,” Schaffner adds.
COVID-19 vaccines are safe and effective at preventing severe illness, hospitalization, and death, according to the CDC. This means they can still offer protection even if someone contracts COVID-19 after vaccination.
The strains targeted by the vaccines are selected over the summer, several months before the shots become available, Pekosz notes. "While the vaccine strain doesn't change, the virus continues to infect people and mutate, so we never have a perfect match," he adds.
However, it appears that the current vaccines will provide protection if the XEC variant spreads widely in the U.S. this fall.
"Now (through October) is a good time to get vaccinated," says Ko. If you’ve recently recovered from a COVID-19 infection, the CDC recommends waiting three months before getting the vaccine, but always consult your doctor.
It's especially important for those at higher risk of severe disease to get the updated COVID-19 vaccine, says Schaffner. High-risk individuals should get vaccinated as soon as possible because the virus is still circulating at relatively high levels nationwide, TODAY.com previously reported.
Experts are concerned that poor vaccine uptake could create a more vulnerable population this winter. "Last year, only 24% of the eligible population received the vaccine, so I hope we do much better this fall," says Schaffner.
"Testing and isolation guidelines"
Current COVID-19 tests are expected to detect the XEC variant and other circulating strains, according to experts.
People should get tested if they have symptoms of COVID-19 or have been exposed. It's also a good idea to test before large events or gatherings, especially if you’ll be around high-risk individuals, says Schaffner.
The CDC recommends staying home if you're sick and returning to normal activities only after being fever-free and having improving symptoms for at least 24 hours.
Antivirals like Paxlovid are still effective and recommended, particularly for those at high risk for severe disease, Schaffner notes. These medications are most effective when taken within the first few days of symptom onset.
"How to protect yourself against XEC?"
As fall approaches, you can take these steps to protect yourself from COVID-19 and other respiratory viruses:
- Stay up to date with vaccines.
- Stay home when sick.
- Avoid contact with sick people.
- Wear a mask in crowded indoor spaces.
- Improve ventilation.
- Maintain good hand hygiene.
- Practice social distancing.
People should get tested if they have symptoms of COVID-19 or have been exposed. It's also a good idea to test before large events or gatherings, especially if you’ll be around high-risk individuals, says Schaffner.
The CDC recommends staying home if you're sick and returning to normal activities only after being fever-free and having improving symptoms for at least 24 hours.
Antivirals like Paxlovid are still effective and recommended, particularly for those at high risk for severe disease, Schaffner notes. These medications are most effective when taken within the first few days of symptom onset.
"How to protect yourself against XEC?"
As fall approaches, you can take these steps to protect yourself from COVID-19 and other respiratory viruses:
- Stay up to date with vaccines.
- Stay home when sick.
- Avoid contact with sick people.
- Wear a mask in crowded indoor spaces.
- Improve ventilation.
- Maintain good hand hygiene.
- Practice social distancing.
.jpeg)
0 Comments