Cases of highly contagious 'Kraken' Omicron subvariant identified in Alberta

The first cases of the new, highly-contagious Omicron subvariant XBB.1.5 have been identified in Alberta.

Nicknamed Kraken, there have been four confirmed cases of the new mutation of the virus, the province said on Wednesday. It is the latest variant to emerge.

"We are monitoring this new subvariant and managing cases as they emerge,"  said Alberta Health spokesperson Charity Wallace. "We encourage Albertans to stay up-to-date on their immunizations."

The variant came about through the fusion of two earlier BA.2 Omicron variants, and it is considered to be more infectious than previous mutations, according to Craig Jenne, an infectious disease specialist.

"It seems pretty good at dodging pre-existing immunity and that could be either immunity that you've developed from catching and recovering from a COVID infection or vaccine," he said.

"The good news though is the immunity, at least the vaccine derived immunity, is still very protective against severe disease."

The XBB.1.5 variant has been spreading quickly throughout the U.S., according to the WHO. It's been detected in more than 25 countries and could trigger more infections rapidly. It is now responsible for around 70 per cent of new cases in the Northeastern U.S.

Alberta Health did not say whether or not they consider this a variant of concern.

"I think what we're seeing already is still reports of a very divergent symptoms in individuals. Like some of the other variants, some people are are getting very mild symptoms, some are getting more severe, some of it is definitely breathing, others it's more of a fever," Jenne said.

"It does not appear to be more severe. So I don't think the evidence is clear that this is a less severe form, but severity seems comparable to what we've been dealing with, with the other Omicron subseries."