Quebec detects 8 cases of highly contagious Omicron 'Kraken' subvariant XBB.1.5, now dominant in U.S.

Quebec's public health scientists confirm they've detected eight cases of the highly transmissible Omicron subvariant XBB.1.5, refferred to by some as the Kraken variant, in COVID-19 test samples.

The results were obtained by sequencing samples from PCR tests that are now only administered to priority groups.

"It still gives us a good idea of what's circulating in the province and even if we don't have the exact number, we can look at the tendencies," said Ines Levade, a specialist in medical biology at Quebec's public health institute (INSPQ).

The INSPQ will update its data when the information becomes available

The subvariant arrived in Quebec in early December. The INSPQ is now monitoring the situation closely because XBB.1.5 is present in at least 30 countries and most concerning, Levade said, has spread rapidly in the U.S.

First detected there in late October, the subvariant soon progressed and became 40 per cent of all sequenced samples in the U.S., and dominant at 70 per cent in the northeast.

"It seems to be doubling every week….we didn't see a growth rate as high," said Levade in an interview with CTV News.

LIKELY NOT MORE VIRULENT BUT 'STILL WORRISOME'

At this early stage, XBB.1.5 doesn't appear to be more virulent, meaning it isn't causing more severe symptoms, but that doesn't necessarily mean it wouldn't cause increased hospitalizations.

"Even if it doesn't cause more severe disease than other Omicron variants, if it's spreading faster, it's still worrisome because the virus is more likely to reach vulnerable people who could be hospitalized and die from the infection," Levade explained.

It's still too early to say how Quebec will fare, however, which is why Levade and her colleagues are keeping a close watch on hospitalization rates in the U.S. and other countries.

Red flags here would come in the form of outbreaks, where XBB.1.5 would turn out to be dominant. Levade said they will continue to sequence samples to get a better snapshot of the situation week to week.

It's a reminder to the population, she said, to maintain hygiene measures to protect themselves and others.

"In Quebec, the virus is still circulating. There are other variants so for sure you still need to be updated in terms of vaccination, wear high-efficiency masks in crowded spaces, if you have symptoms isolate yourself," said Levade.

'NEW MUTATION'

While more studies are needed at this preliminary subvariant stage, one hypothesis explaining XBB.1.5's transmissibility is that a new mutation appears to increase the capacity of the virus to attach itself to the human cell.

More than other strains, "it's really resistant to our antibodies which is the first line of defence to our immune system," said Levade.

The Public Health Agency of Canada says it has detected 21 cases of the XBB.1.5 Omicron subvariant as of Jan. 4.

The agency said Wednesday that they wouldn't be reporting growth rates until there is "sufficient data," but a day earlier said in an email to CTVNews.ca that it’s still “too early” to tell if the variant is spreading in Canada beyond sporadic cases.

“PHAC scientists continue to monitor cases in Canada and track developments internationally,” it stated.