'Kraken' subvariant shows COVID continuing to evolve, vaccine equity needed: experts

One-on-one with Dr. Kieran Moore Ontario's chief medical officer of health Dr. Kieran Moore says residents need remain vigilant against the new subvariant of COVID-19.

Though the Public Health Agency of Canada said last week it’s “too early” to tell if the Omicron subvariant XBB.1.5 is spreading in Canada beyond scattered cases cropping up— there’s still cause for concern and the public should be prepared by engaging in health measures, infectious disease experts say.

And the new variant is an indication that not only is COVID-19 continuing to evolve, it’s highlighting the need for vaccine equity globally to prevent more variants from emerging.

XBB.1.5 is a subvariant of the Omicron variant of COVID-19, nicknamed “Kraken”, and scientists began to warn about a new lineage from Omicron in the fall.

But now, XBB is the dominant variant in the U.S. and officials with the World Health Organization said at a press conference on Jan. 4 that this version of the COVID-19 virus is the most transmissible detected so far.

“The reason for this are the mutations that are within this subvariant of Omicron allowing this virus to adhere to the cell and replicate easily,” said Maria Van Kerkhove, the COVID-19 technical lead for the WHO, at the press conference.

She said XBB has been found in 29 countries so far, but it’s likely in more. Genomic sequencing initiatives have declined world-wide so it’s now harder to track how widespread a variant is, she explained.

And though there’s no evidence so far that the variant causes more severe illnesses, it’s clear XBB is easily transmissible and possibly more immune-evasive, said Dr. Lisa Barrett, an assistant professor in the Department of Microbiology and Immunology and in the Faculty of Medicine at Dalhousie University.

Barrett said in an interview with CTV News Channel Sunday that the vaccines available will continue to work against this new form of the virus.

But, there’s still much we don’t know about COVID-19, and it’s a virus that is mutating more quickly than usual respiratory viruses at the moment. That means the population needs to have continued awareness of COVID-19 and protections, she said.

“COVID is a bit of a master class for the general population, unfortunately, in how viruses evolve,” she said, adding COVID-19 has been given the chance to mutate due to a high abundance of cases.

“This is one of the reasons why we need to continue to do work on COVID…there’s lots we can do about it, good respiratory hygiene culture needs to happen right now,” she said. And countries need to continue to invest in sequencing to better understand variants like XBB.

Barrett encourages people to keep up with their booster shots, wash their hands frequently, stay home when sick and consider wearing a mask in crowded indoor spaces.

On Jan. 4, the Public Health Agency of Canada announced that 21 cases of the XBB variant had been identified across the country.

“XBB.1.5 is currently considered to be only detected sporadically,” PHAC told CTVNews.ca in an email Wednesday. “As data rolls in, growth rates can be more accurately estimated.”

PHAC had not identified XBB as a variant of concern.

According to PHAC data from the week of Dec. 18, close to 94 per cent of sequenced COVID-19 cases were the variant BA.5., another subvariant of Omicron known for its transmissibility.

The creation of variants like Omicron and its subvariants has been fuelled by vaccine inequity, as undervaccinated regions, particularly in the Global South, continue to lack access to vaccines while the West offers multiple boosters and disposed of unused vaccines, according to infectious disease researchers.

In a report published in October, infectious disease experts say the pandemic will be prolonged as new variants emerge from regions of the world that continue to lack access to vaccines to properly inoculate populations.

For now, Canadians are encouraged to get their bivalent booster shot as soon as possible as it’s widely available and will likely prevent serious illness from the XBB subvariant and COVID-19 overall, said Dr. Dale Kalina, an infectious disease doctor with Joseph Brant Hospital and Foundation in Burlington, Ont. in an interview with CTV News Atlantic.

Only about 20 per cent of Canadians age five and older have received a booster shot of a COVID-19 vaccine since Aug. 1, according to the federal government.

With files from CTVNews.ca Writer Alexandra Mae Jones