The first sub-variant of Omicron, the latest major variant of the new coronavirus, was bad. BA.1 caused record cases and hospitalizations in many countries last fall.
The second subvariant, BA.2, was worse in some countries, setting new records for daily cases in China and parts of Europe.
Now BA.1 and BA.2 have been combined to create a third sub-variant. XE, as it is known, is a “recombinant” – the product of two viruses responding “Frankenstein” style in a single host.
With its long list of mutations, XE could be the most contagious form of the coronavirus yet. “The WHO reports show it has a little bit more of an edge on transmissibility,” Stephanie James, head of a COVID testing lab at Regis University in Colorado, told The Daily Beast.
But don’t panic just yet. The same mix of sub-variants that produced XE can also protect we of it. Coming so soon after the spate of BA.1 and BA.2 cases, XE is on track to hit a wall of natural immunity — the antibodies left over from a previous infection in hundreds of millions of people.
Those natural antibodies, plus the extra protection offered by the various COVID vaccines, can mitigate the impact of XE. For that reason, many experts worry less about XE and more about which variant or sub-variant will come after XE.
And rest assured, that future sub-variant is coming. “COVID-19 continues,” Eric Bortz, a University of Alaska-Anchorage virologist and public health expert, told The Daily Beast.
Testers first discovered XE in the UK in mid-January. Six weeks later, British authorities had identified 600 XE infections. Those cases are a proverbial drop in the ocean in light of the millions of BA.1 and BA.2 cases the UK has amassed over the past three months. But XE stood out.
According to the World Health Organization, XE is 10 percent more contagious than BA.2, which itself is up to 80 percent more contagious than BA.1, a subvariant epidemiologists described as the most transmissible respiratory virus they had ever seen when it first appeared in South Africa in November. -Africa.
There is a lot of uncertainty about XE. The WHO stressed that its own finding on the subvariant “requires further confirmation.” But given what we think we know, it appears that XE evolved in someone with overlapping BA.1 and BA.2 infections when two separate but related viruses swapped genetic material.
†We don’t have a roadmap.†
XE isn’t the first COVID recombinant — there have been at least two, including the so-called “Deltacron” subvariant that arose from concurrent Delta and BA.1 infections. But with two highly contagious parent viruses, XE has a chance to be the fastest-spreading recombinant. Health officials have also discovered XE in Thailand.
the sub variant has not not yet turned up in US tests. But that doesn’t mean it hasn’t reached American shores. “It may not be detected by the standard analysis pipeline,” Rob Knight, the head of a genetic computation lab at the University of California, San Diego, told The Daily Beast. Major new forms of SARS-CoV-2 may require changes to test methods.
XE is a nasty bug, because of potentially dozens of mutations in its spike protein, the part of the virus that helps it grab hold of and infect our cells. And it is a strong reminder that the pandemic is not over yet. Even with widespread natural immunity and highly effective and safe vaccines, SARS-CoV-2 continues to find pockets of unprotected people — and opportunities to evolve.
But it’s not 2020 anymore. The new coronavirus has changed, but so have we. Each successive wave of infections – Alpha, then Delta, then both major forms of Omicron – has provided the population with natural antibodies that provide strong, if temporary, protection against the worst effects of future infection by a related form of the virus.
The leading vaccines, meanwhile, have withstood every new variant and sub-variant, especially if you add one or two booster doses.
Even as more and more countries fully reopen schools, businesses and borders, the peak death rate from a COVID wave continues to fall in many countries. Instances can rise if a new subvariant surpasses a previous subvariant and becomes dominant. But deaths aren’t necessarily increasing in the same proportion — a phenomenon epidemiologists call “uncoupling.”
Decoupling is partly a function of the time between waves. Natural antibodies from a previous infection may begin to fade after three months. But if two variants or sub-variants strike within months of each other, the second strain clashes with the immunity left over from the first tribe, especially if the tribes are related. Meanwhile, the second strain produces antibodies that can mitigate the worst results of the next tension, assuming it arrives soon enough.
Therefore, Omicron infected more people than the previous variant, Delta, but killed fewer. And why many experts find XE less scary than BA.2 or BA.1. “Immune responses to XE should be similar to those of Omicron,” Bortz said. “Those with previous Omicron infection and vaccination will be largely immune.”
Likewise, a large gap between individual variants — i.e. a long delay from COVID — could actually be more dangerous to a population than back-to-back-to-back waves of related strains.
There is another risk. We were lucky with the major variants and subvariants before XE, in that the lead vaccines worked very well against all of them. Experts are cautiously optimistic that the jabs will hold up against XE as well. “XE is, as you say, more contagious than BA.2” [or] BA.1,” Edwin Michael, an epidemiologist with the Center for Global Health Infectious Disease Research at the University of South Florida, told The Daily Beast, “but it doesn’t appear to be more severe or immune-evasive.”
But if a new variant, maybe even a recombinant of XE and another strain, eventually mutates in a way that helps evade the vaccines and three months or more after the previous wave of cases arrives, we could be in trouble.
“While mutants have emerged and spread thus far that are more transmissible, there is also the possibility that one will emerge that is both more transmissible and immune-evasive,” Michael said. In that case, none of our approaches to building immunity at the population level — vaccines and natural antibodies — could prevent a devastating spike in deaths.
“We might expect several additional subvariants, but which ones are accelerating — and where — seems uncharted at this point,” Peter Hotez, a vaccine development expert at Baylor College, told The Daily Beast. “We don’t have a roadmap.”
To reduce the chance of the worst outcomes, we need to reduce the possibilities of the coronavirus to mutate. That means reducing the unprotected population. How that we can do this is clear. “Vaccinations are the best way to prevent serious illness,” James said.
Getting pricked not only protects you as an individual from serious infections, it also protects those around you from whatever new variant, subvariant, or recombinant you might mutate in your own body’s lab.