What you need to know about the new type of covid-19 XEC

A new type of covid-19 called XEC has started to spread around the world, especially in Europe. Early evidence suggests it can be transmitted more easily than previous strains, but public health experts say the new strain is very similar to the previous strain and existing vaccines are ineffective against it. Here’s what we know about XEC so far.

What is the new type of covid-19 XEC?

XEC is a combination of two other SARS-CoV-2 strains known as KP.3.3 and KS.1.1. It is created when two species infect the same organism – such as an animal or a human – at the same time, allowing them to share genetic material.

XEC is a genetic offshoot of omicron, a highly transmissible variant that first appeared in South Africa in 2021. “You can think of these new strains as the great-grandchildren or great-grandchildren of omicron,” says William Schaffner of Vanderbilt University. Medical Center in Tennessee. This means that it shares many of the same characteristics as other omicron subvariants, such as spreading easily and causing much less disease than the original SARS-CoV-2 strains.

When and where was the XEC elected?

XEC was first detected in August among covid-19 samples collected in Berlin two months earlier.

The first cases of this type occurred in Italy in May. However, these samples were not entered into the international database that tracks SARS-CoV-2 strains, called the Global Initiative on Sharing All Influenza Data (GSAID) until September.

How many XEC cases are there?

Data from GSAID shows that more than 600 cases of XEC have been reported in 27 countries, including the UK, Germany, Canada and the US. However, “not all countries regularly report data to GSAID, so the XEC version may exist in many countries”, says Bhanu Bhatnagar at the Regional Office of the World Health Organization (WHO) for Europe .

The difference is widespread in Europe, where at least 13 countries have recognized it, says Bhatnagar. So far, XEC makes up about 8 percent of all the samples sequenced and reported from the continent this month, according to data from GSAID. By comparison, it made up 4 percent of samples in August. The most common variant in Europe is still KP.3.1.1 – also in the omicron family – at 48 percent of all samples, says Bhatnagar.

XEC is very common in France, including about 21 percent of consecutive covid-19 samples. It is also increasing in Germany and the UK, where it represents 15 percent and 8 percent of consecutive samples, respectively, says Francois Balloux at the University of London.

The new variant has also been found in the US, where it accounts for about 1% of cases, says Balloux. However, XEC has not yet appeared on the US Centers for Disease Control and Prevention’s (CDC) covid-19 tracker, which includes variants once it accounts for 1 percent of all cases per week.

What are the symptoms of XEC?

So far, XEC causes symptoms similar to other types of covid-19 such as fever, sore throat, cough and muscle pain. “We’ll keep our ears open to see if there are any unique clinical features,” says Schaffner. “We’re skeptical, but we’re always open to that.”

How dangerous is XEC?

XEC does not appear to be more dangerous or cause a more severe disease than previous covid-19 strains, says Schaffner. The WHO has not defined it as another form of anxiety. That’s because it has many of the same characteristics as other omicron subvariants, such as causing milder disease than earlier types, says Schaffner.

Is XEC overrated?

It is too early to say whether XEC is more transmitted than other strains, says James Fielding at the WHO. Because it is already found among other circulating species, however, it may have an advantage that allows it to spread easily.

For example, an early analysis from Mike Honey, a data expert in Australia, suggests that XEC will become the dominant brand in Europe and the UK in October. He predicts the same will happen in the US and Canada later that month or in November.

“How wide [spread] this problem will exist, I think we have to face it,” says Schaffner.

Are covid-19 vaccines still effective against XEC?

The good news is that current covid-19 vaccines are expected to protect against XEC, says Schaffner. This is because updated versions target omicron subvariants.

CDC recommends everyone 6 months or older get an updated covid-19 booster if they haven’t already done so this year. In the UK, booster shots are available for people aged 75 and over, and those living in aged care facilities or those with weakened immune systems.

Ultimately, Schaffner says there’s no need to panic about XEC. “The virus is still evolving, but it seems to be following the same pattern [as past ones]” he says. “My answer is: old, old.”

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