The Omicron subvariant XBB.1.5, known as the Kraken, is ripping through the U.S. and is now in Canada. Here’s what you need to know
XBB.1.5, a new subvariant of COVID-19 that was first detected in October, is now ripping through the northeastern United States, up from nothing a month ago, but now doubling its share of total cases in a week. It is in Canada and two dozen other countries. Concern is high about its rapid and efficient spread, but it does not seem to cause especially bad disease. The National Post’s Joseph Brean runs down the latest details on the Kraken variant, as it is being called.
What is the Kraken?
It is the nickname for a worrying new subvariant of the Omicron strain of COVID-19. “It is on the increase in the U.S. and Europe and has now been identified in more than 25 countries,” said World Health Organization Director General Tedros Adhanom Ghebreyesus on Wednesday, Jan. 4. The WHO’s Technical Advisory Group on Virus Evolution says the “rapidly increasing proportion of XBB.1.5 in the United States and other countries” is an urgent concern and it is preparing a new update in the next few days. The BC Centre for Disease Control says there have been five reported cases of the latest strain as of Tuesday.
Why is this any more concerning than any other type of COVID-19?
A main concern is the speed at which it spreads compared to other subvariants. Cases are surging in the U.S. As of this week, Kraken represented more than 40 per cent of cases in the U.S. The week before that, it was half that figure, and just the third most common variant. At the beginning of December it barely registered at 1 per cent. And in places where it is currently spreading, mainly in the northeast of the U.S., it accounts for almost three cases in every four. That speaks to a subvariant that spreads efficiently despite the accumulated immune protections from vaccines and previous infection with other subvariants. Immunologists call this “immune evasive.”
When did they start naming new variants after mythical beasts? Kraken is already a rum and a hockey team. What happened to the Greek alphabet? Is Cyclops next?
You just never know. But this is a nickname, light-hearted if not actually funny. The official WHO naming convention that follows the Greek alphabet for variants of concern remains in place. Omicron is the currently dominant variant of COVID-19. If it has a successor, it will be called Pi. Kraken is a subvariant of Omicron. Its proper name is XBB 1.5 under the Pango nomenclature system, first devised in the early days of the pandemic based on experience tracking the evolution of influenza viruses. That means it is the fifth generation of the first subvariant of XBB, which is itself a recombinant of sublineages called BA.2.10.1 and BA.2.75. That gets complicated and wordy, so sometimes nicknames are useful. Hence, Kraken.
Are mythological monsters useful nicknames for COVID-19 subvariants?
I don’t know. Hard to say. Let’s ask an expert. T. Ryan Gregory is a professor in the department of integrative biology at the University of Guelph. He studies genome evolution, and he thinks nicknames are as useful for experts as for the general public. A few months ago, it would not have mattered as much, he said. The various Omicron waves were genetically distinct. Now, there’s an “alphabet soup” of subvariants. 650 have technical names. Now, talking about the Greek letter variants is like talking about “mammals” instead of “cats.” It is too vast a category. The Pango names, on the other hand, are like Linnaean taxonomy, like talking about “Felis catus” instead of “cats.” They are too technical and impenetrable. “We don’t give common names to everything,” he said. “We give them to things we’re talking about outside of technical discussion.” He is part of a chat group of genomic researchers, and after the first subvariant monster nickname Centaurus (father of the half-man, half-horse race of centaurs) took off on social media, they started proposing similar nicknames whenever they seemed useful, with no formal process. Centaurus is also a constellation, but monsters became the style, some from Greek myth, some from Norse. They are not chosen to be scary especially, or to cause alarm, but rather to be distinct. “Beyond that, it’s pretty arbitrary,” Gregory said. Others include the famous human-headed winged lion Sphinx (BA.5.1), the bull-headed human-bodied Minotaur (BF.7) and Cerberus (BQ.1.1), the three-headed dog that guards the gates of hell.
Reminder that nicknames are available if you’re trying to communicate about these and don’t agree that they are not sufficiently divergent. These are informal names, but they have been picked up in quite a few news stories. Use them if they are helpful. Don’t if they’re not.
— T. Ryan Gregory (@TRyanGregory) October 28, 2022
Still sounds menacing. Is the Kraken virus as scary as its namesake giant octopus?
It’s looking good so far. When it was reported in October, early evidence from India suggested Kraken’s clinical severity was not especially high, meaning it did not lead to worse disease than other types. “While further studies are needed, the current data do not suggest there are substantial differences in disease severity for XBB* infections. There is, however, early evidence pointing at a higher reinfection risk, as compared to other circulating Omicron sublineages. Cases of reinfection were primarily limited to those with initial infection in the pre-Omicron period,” the WHO Technical Advisory Group said. That view seems to be holding up in the United States. The Centers for Disease Control reported that areas where XBB 1.5 is spreading are not showing disproportionate rises in hospitalization.
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