Why not “pi”? Variants are still trapped in the Omicron even as the coronavirus continues to mutate

You may have heard that there is a new spin-off from Omicron that is rapidly gaining ground in the United States. You might want to ask your doctor about it or look up more information online – but what is it called again?

Exactly.

Scientists know it as XBB.1.5, a name given because it is the second generation of the recombinant Omicron subvariant XBB.

X is the way scientists call a recombinant, the result of two viruses swapping sections of their genetic material. The BB part is alphabetical order only. The first known recombinant was named XA, the second XB and so on. Now they’ve gone through the alphabet and are doubling: XAA, XAB, all the way to XBB.

It wasn’t always this difficult.

In May 2021, the World Health Organization (WHO) announced that, to allow better public communication and avoid the stigma of naming new variants with the names of the countries where they were found, it would assign Greek letters to viruses that had acquired mutations that the make them more transmissible, help them evade current therapies, or make them more severe.

The WHO said it would give these new names to viruses that its experts have designated as “variants of concern” or even more important variants “of concern”. This gave us the familiar Alpha, Beta, Gamma and Delta variants, as well as a host of others that only gained regional importance, such as Epsilon, Theta and Mu.

It’s been over a year since the WHO gave a new variant a Greek letter name. However, it has created a communication gap that some experts believe may be hampering efforts to protect public health.

Where did the Greek letters go?

When Omicron – also known as BA.1 – spread around the world starting in November 2021, it was so genetically distinct from the viruses that came before it that its branch of the SARS-CoV-2 family tree headed off in an entirely different direction.

Our immune system barely recognized it. BA.1 generated new waves of infections, hospitalizations and deaths, in addition to a series of new descendants.

At the time, scientists argued that the second Omicron strain – BA.2, with dozens of new genetic mutations – was as genetically distinct from BA.1 as Alpha, Gamma and Delta were from each other. Some said they thought BA.2 deserved its own Greek letter.

But that never happened. Instead, the WHO has quietly stopped designating categories of variants of concern or variants of interest that require new Greek names.

Instead, it created a new category, Omicron Subvariants Under Monitoring, to flag public health officials which of these spinoffs to look out for—which might sound like a lot of reason to designate variants of interest and variants of concern in the first place.

The organization left the door open to assign new names if it deems a sufficiently different variant, but didn’t see the need to do so for over a year.

However, the coronavirus has continued to evolve, becoming more transmissible and more immunoevasive over time. These changes were also consequential.

As Omicron has mutated, for example, immunocompromised patients have missed out on important therapies such as preventive Evusheld long-acting antibodies. Monoclonal antibodies developed to help people with severe Covid-19 infections have lost their power against newer subvariants.

Messenger RNA (mRNA) vaccines have also been updated in an effort to better protect people from the circulating viruses that cause Covid-19.

Still, the WHO says it sees no need to make a distinction.

“The fact that many individual (sub)variants are not given their own label does not diminish the importance of these variants,” WHO spokesman Christian Lindmeier said in an emailed statement.

“A new label (i.e., a new assignment of a variant of concern) would be given if there was a variant sufficiently different in its public health impact that it would require a change in the public health response,” Lindmeier wrote.

false sense of security

Some scientists say they agree with this strategy.

“Actually, I’m fine with not providing new Greek letters for subvariants of Omicron,” wrote Michael Worobey, a computational biologist who studies pandemics through genomics and viral evolution at the University of Arizona, in an email to CNN .

Worobey points out that there are two ways in which the coronavirus has been changing over time. The first is on the move, continuing to circulate and infect people around the world. This type of evolution happens more incrementally and usually doesn’t cause big changes all at once.

The second way viruses change is by “camping,” chronically infecting people with impaired immune function. A person in Houston was tested in October and found to be infected with a version of the Delta variant that acquired 17 mutations in its genome, Worobey said. There is another patient in Spain with almost the same number of mutations.

Worobey says these viruses have the potential to create another Omicron-level surge, and he’s fine with not naming it “Pi” until one of these “zombie viruses” emerges and starts spreading.

But others think the WHO’s shift in strategy could be misleading.

“The variants within Omicron are really pronounced and distinct. It’s not like Omicron is one thing. It has evolved enormously,” said Bette Korber, a researcher and expert on variants at the Los Alamos National Laboratory.

Korber says that even when Omicron was born, it had two “parents”, BA.1 and BA.2.

And each one continued to evolve, so scientists have recorded more than 650 subvariants and substrains within the Omicron strain.

“But the WHO has stopped naming them at this point, so [as pessoas] have a false sense of security,” said Korber. Continuing to use the name Omicron makes it appear that the virus is no longer changing, “but in fact it is changing a lot”.

Korber said he has attended public lectures where “very good doctors” have said, “’Well, now it’s not evolving anymore. It’s been Omicron for over a year now, so you don’t have to worry about it anymore.”

Looking for better ways to communicate

Ryan Gregory, an evolutionary biologist at the University of Guelph in Canada, says that without new Greek letter names, we lose the ability to easily communicate about the virus.

“If you said ‘what’s that rustling in the weeds?’ and someone else said ‘a mammal’, well that’s not especially helpful right? It’s not enough information.”

Scientific names for sublines like BQ.1.1 are very accurate, he says, but quickly become unwieldy. It’s like calling a bush mammal by its Latin name, mus musculus.

“What is missing is the equivalent, in animal and plant taxonomy, of the common name. So if you said ‘what is that’ and I say ‘is it a mouse or a rat’, now you know exactly what I’m talking about”, he said.

It’s so frustrating even for scientists to discuss subvariants that Gregory decided to create his own nickname for XBB.1.5: Kraken, after the mythological sea monster. Got it so far.

He is not the first to take on the task. Before Kraken, social media users called the BA.2.75 subvariant Centarus. It was also a success.

Gregory says the names stuck because they serve a purpose, allowing people to have thoughtful discussions about the virus, its changes and how it might affect them.

But DIY nomenclature is not a perfect solution as it is not exactly standardized. Mention Kraken to someone who isn’t on Twitter and they might not know what you’re talking about.

“My strong preference would really be that we don’t need names because we haven’t seen the constant evolution of many other variants that we need to watch. That will be for the best because we mitigate them,” said Gregory.

But a second step would be a formal nomination system handled by appropriate groups that would be used specifically for communication so people can be kept up to date, he said.

“Not to cause panic, obviously, but to let people be informed and not get lost in the obviously technical stuff.”