XEC is now in Australia. Here’s what we know about this hybrid variant of the SARS-CoV-2 virus

In the nearly five years since the emergence of the Covid-19 virus, you’d be forgiven for forgetting the number of fresh variants we’ve seen. Some have had a greater impact than others, but documented by virologists thousands.

The latest variant that is making headlines it’s called XEC. This omicron subvariant has been reported mainly in the northern hemisphere, but is now occurring detected in Australia too.

So what do we know about XEC?

Is Covid still relevant?

People are less likely to test for Covid-19 and less likely to report it. Enthusiasm for track the virus generally decreasing.

However, Australia continues to collect data and report Covid data. Although the number of cases is likely to be much higher than documented (approx This year already 275,000), we can still tell when we see significant waves compared to periods of lower activity.

Australia has recorded its latest peak in Covid-19 cases of the year June 2024. Since then, the number of cases has been decreasing.

But SARS-CoV-2, the virus that causes Covid, is certainly still around.

What variants are currently in circulation?

Main Covid variants currently circulating around the world are BA.2.86, JN.1, KP.2, KP.3 and XEC. They are all descendants of Omicron.

This is the first time the XEC variant has been detected in Italy in May 2024, the World Health Organization (WHO) described it as a variant “under monitoring“in September.

From the moment of detection XEC has spread to over 27 countries in Europe, North America and Asia. As of mid-September, the most cases were reported in countries such as the United States, Germany, France, Great Britain and Denmark.

XEC is currently catching up 20% of cases in Germany, 12% in the UK AND in the USA about 6%..

Although XEC remains a minority variant worldwide, it appears to have a growth advantage over other circulating variants. We don’t know why yet, but reports suggest it may be possible spread more easily than other variants.

For this reason, it is predicted that XEC may become the dominant variant worldwide in the coming months.

How about Australia?

Latest Australian Respiratory Surveillance Report it has been noted that an increasing proportion of sequenced XECs has been observed recently.

In Australia, 329 SARS-CoV-2 sequences collected from August 26 to September 22 were uploaded to the website AusTrakkaAustralia’s National Genomics Surveillance Platform for Covid-19.

The most sequences (301 of 329, or 91.5%) are JN.1 sublines, including KP.2 (17 of 301) and KP.3 (236 of 301). The remaining 8.5% (28 of 329) were recombinants consisting of one or more omicron sublineages, including XEC.

Estimates based on data from GISAID, the international repository of viral sequences, suggest that XEC is catching up about 5% of cases in Australia or 16 of 314 samples were sequenced.

Queensland reported the highest rates over the last 30 days (8% or eight of 96 sequences), followed by South Australia (5% or five of 93), Victoria (5% or one of 20) and Up-to-date South Wales (3% or two of 71). WA recorded zero sequences out of 34. No data was available for other states and territories.

What do we know about XEC? What is a recombinant?

The XEC variant is believed to be the recombinant descendant of two previously identified omicron subvariants, KS.1.1 and KP.3.3. Recombinant variants arise when two different variants infect a host at the same time, allowing the viruses to swap genetic information. This leads to the emergence of a fresh variant having features of both “parent” lines.

KS.1.1 belongs to a group commonly known as “FLiRT” variantswhile KP.3.3 is one of the “FLuQE” variants. Both of these groups of variants have contributed to the emergence of recent ones increase in the number of Covid infections all over the world.

WHO naming conventions for fresh COVID variants, letter combinations are often used to designate fresh variants, particularly those that arise from recombination events between existing lineages. “X” usually means: recombinant variant (such as XBB), while the letters following it identify specific lineages.

So far, we know little about the features of XEC and how it differs from other variants. However, there is no evidence to suggest that symptoms will be more severe than with earlier versions of the virus.

We only know what mutations this variant has. In the S gene encoding the spike protein, we find the T22N mutation (inherited from KS.1.1), as well as Q493E (from KP.3.3) and others mutations
known to omicron pedigree.

Will vaccines still work well against XEC?

Latest monitoring data does not show a significant boost in the number of hospitalizations due to Covid-19. This suggests that current vaccines still provide effective protection against the severe effects of circulating variants.

As the virus continues to mutate, vaccine companies will continue to do so continue to update your vaccines. Both Pfizer and Moderna have updated vaccines targeting the JN.1 variant, which is the parent strain of the FLiRT variants and therefore should protect against XEC.

However, Australia is I’m still waiting to find out which vaccines may be made available to the public and when.

In the meantime, omicron-based vaccines such as the current XBB.1.5 spikevax (Moderna) or COMIRNATY (Pfizer) vaccines are still likely to provide good protection against XEC.

It’s strenuous to predict how XEC will behave in Australia once summer arrives. We will need more research to better understand this variant as it spreads. However, given that XEC was first detected in Europe during the northern hemisphere summer months, this suggests that XEC may be well suited to spread in warmer weather.