What you need to know about the new COVID variants

A new COVID variant is spreading rapidly and may soon become the predominant variant around the world. This variant, called XEC, August in Germany Although it appears to have a growth advantage over other circulating variants, it is not a fundamentally different variant.

XEC is what's called a “recombinant variant,” and recombination can occur naturally when someone is infected with two different COVID variants at the same time.

XEC arose by recombination (the exchange of genetic material between two mutants) between the KS.1.1 and KP.3.3 mutants. These two parent mutants are closely related and both have undergone evolution. From JN.1By early 2024, it had become the dominant variant worldwide.

XEC was the first Reported The outbreak began in Germany and other European countries in early August 2024 but has continued to spread since then, with more than 600 confirmed cases in 27 countries across Europe, North America and Asia.

Scientists describe cases of XEC as ” GishideThe genetic sequence of the virus is then uploaded for analysis, where mutations of SARS-CoV-2 (the virus that causes COVID) are discovered.

But this is a bit like a drunk person looking for his lost keys under a streetlight because that's where it's best lit. In other words, countries that are sequencing more COVID samples than usual through their regular surveillance programs are finding more cases of the new variant.

As of September 18, countries with confirmed cases of XEC are the United States (118), Germany (92), the United Kingdom (82), Canada (77), and Denmark (61). Of course, these figures could be higher in countries that do not routinely sequence COVID samples.

Currently, the predominant variant in Europe and North America is KP.3.1.1, while the closely related KP.3.3 dominates in Asia.

XEC is a minority variant and its prevalence is highest in Germany, where around 13% of sequences are likely XEC. In the UK, the prevalence is around 7%, while in the US it is less than 5%. However, XEC has a growth advantage and is spreading faster than other circulating variants, suggesting that it could become the dominant variant worldwide within the next few months.

XEC has highly similar genetic material to both its parent variant and other circulating variants that are primarily derived from JN.1.

One reason for XEC's advantage may be the combination of the relatively rare T22N mutation (inherited from KS.1.1) and Q493E (from KP.3.3) in the spike protein. The spike protein is a critical part of the virus that binds to human cells, allowing the virus to enter and begin replicating. However, little is known about how the T22N mutation affects the virus' ability to replicate and spread between people.

But does it make the disease worse?

There is no data yet from patients or laboratory experiments that would indicate what kind of illness XEC may cause, but this data is expected soon. However, this new variant may be similar to other COVID variants in terms of the illness it causes, due to similar genetic information. Therefore, symptoms such as high fever, sore throat with cough, headache, body aches, and fatigue are expected.

Hospitalizations typically increase in winter as a result of cooler temperatures and increased virus spread (as people spend more time indoors), so when these increases occur they are not necessarily linked to the new variants.

The UK's autumn booster vaccination campaign will begin in October with an updated vaccine targeting the JN.1 variant from which XEC is derived, ensuring a high level of protection against severe disease.

XEC is the latest in a long list of past and current COVID variants being monitored as the virus naturally evolves. Recombinant variants themselves are not new, and COVID cases in 2023 have been dominated by XBB recombinant variants.

Several other closely related variants are also being monitored, including the MV.1 variant, which, like XEC, has the T22N mutation in the spike protein. MV.1 was first reported in India in late June and has spread rapidly to other countries and will continue to be monitored.

While XEC is likely to become the globally dominant variant, it may be out-competed before then, or replaced by a different but closely related variant soon after.