Latest COVID-19 variant wrestles its way to the top in Alberta

A new COVID-19 variant appears to be on its way to taking over in Alberta, with one expert predicting it likely already accounts for the lion's share of the province's cases.

JN.1 is an offshoot of BA.2.86, which has evolved, like many of its predecessors, to better evade our immune defences.

It is now the dominant strain in Canada. Data from the Public Health Agency of Canada shows it accounted for about 66 per cent of COVID-19 cases nationwide by the end of December.

And it's on the rise as a proportion of cases in Alberta, too.

Data provided by Alberta Health shows that as of the week of Dec. 23, JN.1 had been identified in approximately 45 per cent of sequenced cases.

The week before, it accounted for 26.4 per cent, according to the publicly available respiratory virus dashboard.

"It's likely becoming — or has become — dominant in Alberta," said Dr. Lynora Saxinger, an infectious diseases specialist at the University of Alberta.

"But with that we're not necessarily seeing any change in the severity of illness or type of illness or hospitalizations."

JN.1 was classified as a variant of interest in Canada on Dec. 21. The designation is reserved for variants the Public Health Agency of Canada (PHAC) believes have the potential to replace a dominant lineage, where the impacts are unknown or not expected to be "meaningfully different than current lineages."

In an email, a PHAC spokesperson said the agency is watching to see if JN.1 warrants being bumped up to a variant of concern.

That label is given to lineages that "are expected to have a meaningful impact on population level outcomes beyond what is happening with the current lineages," the PHAC website states.

Dr. Lynora Saxinger is an infectious diseases specialist at the University of Alberta. She says outcomes do not appear any different with the JN.1 variant and hospitalized patients don't appear to be more seriously ill. (Peter Evans/CBC)

According to experts, JN.1 shows an advantage because it appears to more easily evade immunity.

"It emerged in the fall and it didn't really take over. But it has been quite successful and it has a couple of extra mutations in the spike protein that just give it that extra edge on transmissibility," said Caroline Colijn, a Canada 150 Research Chair in mathematics for evolution, infection and public health at Simon Fraser University.

In a statement emailed to CBC News, a PHAC spokesperson said current transmission trends show JN.1 is expected to steadily increase as a proportion of cases in the coming months.

"In early December 2023, the WHO indicated that the current public health risk for JN.1 was considered to be low and not greater than currently circulating Omicron descendant lineages, despite an increase in cases," the spokesperson said.

"While presently limited, the evidence to date does not suggest any associated increases in disease severity."

Alberta Health also said outcomes do not appear any different with this variant, and Saxinger said hospitalized patients don't appear to be more seriously ill.

"It's a little bit early to say for sure, but so far it hasn't seemed to make much of an impact on how much COVID we're seeing because really we were very occupied with flu," she said.

"But COVID numbers have been dropping over that same time period, so I don't think it's likely to cause any big ripples in the short to medium term."

JN.1 is the latest sublineage to wrestle its way to the top as the SARS CoV-2 virus circulates globally.

"We've seen this time and time again with variants, where you have one variant that has an advantage over others," said Colijn.

With limited testing, it's difficult to understand the risk of new variants, according to Colijn. It's possible, she said, that JN.1 could lead to an uptick in overall case numbers.

"If you have a transmissible or immune evasive — or both — variant, then it will rise in numbers as well as frequency," she said.

"I think you could be looking at a surge. And the Alberta health system is already struggling with waiting times and capacities, so any surge that does happen from this variant could add to that."

Meanwhile, PHAC is urging Canadians to get the latest COVID-19 vaccine.

"Early evidence suggests that the updated XBB.1.5 vaccines provide protection against these latest circulating strains," a spokesperson said.

"Getting an updated COVID-19 vaccine continues to be one of the most effective ways to protect against serious illness, hospitalization and death from COVID-19. It also reduces the risk of developing post-COVID-19 condition."

Just 16 per cent of  Albertans have received the updated COVID-19 shot.

"Certainly people hearing this news should really look at when their last vaccine was," said Saxinger.

"If it was the bivalent vaccine, getting the fall vaccine — the XBB vaccine — would be an advantage to them."