Coronavirus: Hunting for variants and the case for travel restrictions

Click to play video: 'COVID Variants: Will they cause Canada’s third wave?'
COVID Variants: Will they cause Canada’s third wave?
WATCH: All three highly contagious coronavirus variants have been found in Canada, sparking a debate about the need for stricter travel measures and new demands for genomic sequencing. Dawna Friesen explores our strategy to detect and disrupt the spread of the variants before they cause a third wave – Feb 13, 2021

As highly-infectious variants of the novel coronavirus spread around the world, there are mounting questions on how best to keep Canadians safe.

Once again, travel is in focus as attention shifts from declining cases in Canada to these new threats from abroad.

All viruses must move to survive, but are helpless without their human hosts. And yet there remains widespread reluctance to restrict travel.

“We’re looking at really every measure that’s been implemented by every country,” Simon Fraser university professor Kelley Lee told Global News.

Lee is part of an international group analyzing travel restrictions.

“So at the beginning, way back in January, February, the received wisdom really was that travel-related restrictions don’t work and WHO (the World Health Organization) put out a recommendation that countries should not adopt such measures.”

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As the pandemic has unfolded, opinions have shifted, Lee says. “We’ve seen that actually there are some situations where actually it can work.”

Australia and New Zealand are often held up as success stories. Life in both countries is largely back to normal, having pursued aggressive strategies that include extremely tight border controls and strict lockdowns when even a single case emerges.

Hunting for variants in Canada

A genetic hunt is underway as Canadian scientists in a sophisticated, nationwide network of labs aim to detect and disrupt the new and highly contagious U.K., Brazilian and South African variants of the coronavirus.

Labs in Canadian COVID-19 Genomics Network (CanCOGeN) are sequencing samples from positive COVID-19 tests.

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Genomic sequencing involves mapping out the entire genetic profile of a given viral specimen. It’s the only way to determine the extent of variants in the population.

READ MORE: COVID-19 variants could be spreading across Canada. Are labs doing enough to detect them?

Dr. Catalina Lopez-Correa is the executive director of the nationwide network, which is made up of dozens of provincial and academic labs. It was created last March in anticipation of the need to ramp up genomic sequencing of SARS CoV-2 variants.

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Roughly five per cent of all positive COVID-19 tests in Canada are selected for sequencing. Crucially, scientists in the network remain in close contact with counterparts around the world, all in an effort to stay ahead of mutations of the virus.

Global News asked if sequencing just five per cent is enough to determine the prevalence of variants within the Canadian population.

“This is the one million dollar question. We have been working with modellers, mathematicians, statisticians to get to the right number,” Lopez-Correa told Global News.

She added, “We need to do more. It will be important to do more sequencing, to really get a detailed information on what’s happening with these (variants) and not just in Canada.”

READ MORE: Variant from U.K. could ‘threaten vaccination’ and ‘sweep the world’: expert

Using this method, they’ve successfully managed to identify cases of all three variants in Canada. But could these detected cases be just the tip of the iceberg? Lopez-Correa said it’s difficult to know right now where we are on the epidemiological curve.

“The virus is fast in learning how to trick our system. We need to be fast in learning how is the virus moving and how is the virus evolving.”

Concerning Brazil Variant

Here is what we know so far about the variant from Brazil:

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Brazil is currently battling at least two different variants – P.1 and P.2 – driving a surge cases in the country.

According to a Lancet study published on Jan. 27, up to 76 per cent of the population of Manaus, in Brazil, had been infected with COVID-19 by October last year, which is above the theoretical threshold for herd immunity.

READ MORE: ‘Concerning’ Brazil COVID-19 variant found in Canada. What you need to know

The P.1 variant, also known as B.1.1.28, was first detected in January in four Japanese travellers who had returned from Brazil’s Amazon region. Canada’s lone case of the Brazil variant is of the P.1 lineage.

According to the U.S. Centres for Disease Control and Prevention, this P.1 variant has 17 unique mutations, including three in the receptor binding domain of the spike protein of the virus — which is responsible for cell entry.

So far, there is little evidence about how contagious the Brazil variant is, but it shares several independently acquired mutations — N501Y, K417N/T, E484K, N501Y — circulating in the U.K. and South Africa variants, which seem to have increased transmissibility.

“It is expected to behave just like the U.K. and South African variants and show this increased transmissibility,” Dr. Donald Sheppard, an immunologist and microbiologist at McGill University Health Centre, told Global News.

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Dr. Andrew Pekosz, a virologist and professor of microbiology at the Johns Hopkins Bloomberg School of Public Health, said,“It has an odd combination of mutations, which makes it much more of a … potential threat to humans than the older strains of SARS-CoV-2.”

— With files from Saba Aziz 

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