While most of us would prefer to forget about COVID-19 entirely, the virus continues to spread across the world’s population and mutate along the way.
The number of COVID-related deaths and hospitalizations has decreased in most countries in recent months since the height of the pandemic in 2020, although a big question mark still hangs over the number of current infections in China.
But a new subvariant of Omicron, which has emerged in countries like the UK and US, is now raising the question of whether we should continue to worry about the latest strains of COVID-19.
This new subvariant is officially called “XBB.1.5” and is the result of fragments of two other variants merging together – what is called a “recombinant subvariant”.
“Two different strains of BA.2 Omicron somehow converged together to create this,” explained Sheena Cruickshank, a professor at the Lydia Becker Institute of Immunology and Inflammation at the University of Manchester.
“But it’s really just a descendant of XBB and XBB.1. I mean, it’s like a grandson of XBB, which itself is from two different versions of BA.2.”
Where was XBB.1.5 found?
The subvariant, which was renamed “Kraken” (after the legendary sea monster), is estimated to have originated between November and December 2022 in or near the state of New York in the United States.
The strain is now thought to be responsible for the rise in infections across the country, where it is estimated to be the cause of 41 percent of current COVID-19 cases, according to data from the U.S. Centers for Disease Control and Prevention (CDC). ).
After the United States, the new strain has been reported in Europe, Australia and parts of Southeast Asia.
In the UK, where the strain has also been detected, Cruickshank says the strain “only accounts for around 4% of cases at the moment, but we’re seeing it double quite rapidly.”
Is it more dangerous than other strains?
Cruickshank says it’s too early to tell whether Kraken is more dangerous than other strains, but adds that “we have no data to suggest that’s the case.”
While this is certainly a good thing, he says the number of COVID-19-related hospitalizations in the United States is increasing, “and this is where we appear to have first gotten evidence of this particular variant.”
But whether it’s because the variant is “badder,” says Cruickshank, “we don’t know. We just don’t have the proof.”
Cruickshank believes that since most of the population is vaccinated, any new infections should be less severe. “So, we have some protection,” he said.
Should you be concerned about the “Kraken”?
The strain appears to have raised concerns among epidemiologists and experts.
Dr Maria Van Kerkhove of the World Health Organization (WHO) said during a press conference earlier this week that the new subvariant is a cause for concern for the organisation.
“We are concerned about its growth advantage particularly in some countries in Europe and the United States…particularly in the northeastern part of the United States, where XBB.1.5 has rapidly replaced other variants in circulation,” he said.
“Our concern is how transmissible it is…and the more this virus circulates, the more opportunities it will have to change.”
Epidemiologist Dr Eric Feigl-Ding, who wrote about the spread of XBB.1.5 on Twitter on Dec. 29, said the new subvariant “is both more immune evasive and better at infecting than #BQ and XBB.”
According to Feigl-Ding, who accused the CDC of failing to warn Americans earlier about the new subvariant and withholding data on the subvariant’s circulation, the strain “is likely an American-origin recombination variant that is 96 percent faster (worse) than the old XBB,” he wrote on Twitter.
“XBB.1.5 popped up in the New York area in October and [has] been causing problems ever since”.
The Kraken, Feigl-Ding says, is behind “the largest COVID-19 hospitalization in nearly a year” in New York.
Cruickshank thinks we should “be vigilant” about the new variant.
“What’s special about this virus is the mutations it has acquired. So all viruses mutate and pick up mutations as they replicate in our cells, it’s normal because viruses replicate very quickly. These mutations will accumulate,” he said.
“And what you tend to see over time is the kind of mutations that benefit the virus will start to become dominant. And what this XBB.1.5 or Kraken has the ability to try to avoid our antibodies.
“So that means whatever immunity we have from vaccines and more or less the previous infection may not be as effective. So it has an immune evasion mechanism.”
These virus-developed immune evasion mechanisms come with something of a “cost” to COVID-19, Cruickshank explains, “because trying to avoid our antibodies often means the virus is a little less able to enter our cells.” “. .
But in the case of the Kraken variant, XBB.1.5 “worked around this problem,” says Cruickshank.
“It’s both able to avoid the immune system, but it’s also able to get into our cells incredibly well. So it seems to have an edge. An infectious edge. And I think that’s why we’re seeing numbers take off just like we are.” “.