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‘Minefield’ of variants: How the California strain is different from the others

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As COVID-19 snakes through cities and countries, it has changed, morphed and mutated.

The latest iteration of the respiratory disease making waves is one first identified in California. The Western state is now teeming with the variant, known as B.1.427/B.1.429.

Its recent role in creating a heavily-mutated virus hybrid has raised eyebrows worldwide, but experts are growing increasingly concerned about its individual behaviours.

Here’s what we know so far:

How is it different?

“A lot of the variants have very common mutations,” said Gerald Evans, chair of the infectious diseases division at Queen’s University in Kingston, Ont.

The N501Y mutation, for example, is found in the variants that arose in the U.K, South Africa and Brazil. It’s known to make the virus spread easier.

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The scientific title for it is “positive convergence,” which means the mutation is “favoured by the virus because it does something to increase its transmissibility,” or to try and dominate, Evans said.

“The California variant, at the moment, does not appear to be a subset of any other variants,” he said.

Read more: What the COVID-19 variants could mean for masks, lockdowns and vaccines

So what does it have?

The variant detected in California has a mutation called L452R, which is located in a critical portion of the spike protein. Experts believe it has the potential to make current vaccines less effective.

“This is something that should be carefully monitored,” said Levon Abrahamyan, a virologist at the University of Montreal.

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He said the mutation isn’t entirely new, though. It has circulated in Denmark and other parts of the world but has increased in the U.S. in recent months.

Read more: PHAC monitoring reports of 2 COVID-19 variants merging into heavily mutated hybrid

While it hasn’t been studied extensively, it’s possible the mutation gives the virus an advantage at spreading over other variants. Roughly 45 per cent of current samples in California show this mutation, according to a report by the New York Times.

“But it’s not always that clear cut,” said Abrahamyan. “It’s not always true that anything proven in a lab will be reproducible in the real world.”

What do researchers think?

Researchers in California have been looking more closely at the B.1.427/B.1.429 variant since December when it first came up in sequencing done by the University of California.

By late January, it became the predominant variant in the state.

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Two recent studies suggest how that might have happened, and what risk it poses.

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In one, published in The New York Times, researchers found that the variant spread rapidly in a San Francisco neighbourhood, suggesting it could be more transmissible.

But it’s “hard to distinguish,” said Evans. Many of these studies are preliminary and don’t account for “confounders” — something that hasn’t been accounted for but could have predicted the outcome, like a superspread event or gathering.

“It took a long time in Britain to truly decide that the U.K. variant is more transmissible,” he said.

In the other report, scientists contend that the variant produces twice as many viral particles inside a person’s body as other variants do, which suggests that it could be associated with more severe illness and death.

Read more: How prevalent are variants? A closer look at what — and where — they are in Canada

That same study also hinted that the variant may be better than others at evading both vaccines and the immune system. In lab studies, antibodies from people who recovered from other COVID-19 versions were less effective at blocking the new variant.

Evans suspects this relates to the L452R mutation. Since the mutation is known to impact the spike protein, it could affect the binding of certain therapeutic monoclonal antibodies — or COVID-19 treatment drugs.

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Monoclonal antibody drugs — particularly common in the U.S. — are a cocktail of laboratory-made antibody proteins that mimic the immune system’s ability to fight off viruses. Emerging research hints that some variants have mutations that can render such treatments ineffective, meaning new ones specific to certain strains may need to be developed.

“It’s the only country rich enough to purchase and use these in vast amounts,” Evans said.

“It’s similar to antibiotic resistance … Because of the massive use of these antibodies to treat people, they’re selecting out these particular kinds of variants that are resistant to monoclonals.”

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The effect on vaccine efficacy — which also uses antibodies to fight infection — is still being tested.

“Now that … that wouldn’t be good,” Evans said.

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Experts still aren’t sure how much of a threat this variant poses compared with others spreading in California and in other parts of the world, including Canada. It should be noted neither study has been published in a scientific journal.

There’s no reason to be “alarmist” quite yet, said Abrahamyan.

“I’m skeptical,” he said. “For the most part, these vaccines have been evaluated for all these various variants. The possibility that mutation will develop a resistance to vaccines, it’s very low — nearly zero, I’d say.”

Read more: Booster shots, new clinical trials: What the COVID-19 variants could mean for vaccines

What about Canada?

The problem for Canada will be finding this variant from California, Evans said.

Labs across Canada have significantly scaled up their ability to identify cases of COVID-19 variants in recent months and there is increasing pressure to keep up.

As of now, surveillance is laser-focused on the three main “variants of concern” (VOCs) — those first identified in the U.K., South Africa and Brazil — all of which have been detected in Canada.

Therein lies the potential problem, according to Evans.

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“Canada is mainly screening positive samples by testing it against the N501Y mutation. The thing about the California variant is that it doesn’t appear to have that N501Y mutation, so it wouldn’t be detected,” he said.

“The problem with that system is that if we get this variant — or a variant like this — that does not have that mutation, it’s going to slip under the radar.”

The Public Health Agency of Canada experts are closely monitoring genetic variants of the virus. Canada has so far logged more than 800 cases with VOCs.

As it stands, there are no publicly known cases of the B.1.427/B.1.429 variant in Canada. However, the agency did not respond to a request for comment on the variant in Canada by time of publication.

Read more: COVID-19 variants leave less ‘room for error’ in loosening restrictions

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Overall, Evans isn’t all that concerned.

Travel tends to be the main way these variants hop across a map. With traffic between the U.S. and Canada significantly down, and new travel restrictions offering a fresh deterrent, Evans is “cautiously optimistic” Canada won’t have to deal with this variant.

“Or we’ll find out that it’s not actually any more dangerous than the ones we’re currently worried about and dealing with,” he said.

“Regardless, I think these variants have woken everybody up … We’re in a bit of a minefield right now.”

— With files from The Canadian Press 

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