Canada has reported a first case of a new potentially more contagious Brazilian variant of the coronavirus.
“It is concerning that this one has been found in Canada,” said Dr. Isaac Bogoch, an infectious disease specialist at the University of Toronto, said.
“This has several mutations in the virus.”
Over the past month, a number of cases of variants of concern have been found in Canada.
As of Tuesday, there were more than 355 cases of the more transmissible B.1.1.7. variant, which was first discovered in the U.K., and at least 25 people having tested positive for the B.1.351 variant, also known as the N501Y.V2 variant, which was discovered in South Africa.
Here is what we know so far about the one from Brazil:
Brazil is currently battling at least two different variants – P.1 and P.2 – that have led to an uptick in 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 coronavirus by October last year, which is above the theoretical threshold for herd immunity.
The P.1 variant, also known as the 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.
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.”
The experts say it is natural for all viruses to mutate, as their genetic material undergoes small changes during outbreaks.
Biologically, certain mutants give the spike protein a higher affinity for the receptor molecule on a healthy cell membrane, meaning the virus latches on to the human cells more effectively.
Levon Abrahamyan, a virologist at the University of Montreal, said like with older strains of the virus, social factors can also influence a certain variant’s probability to infect people.
“A large gathering of people in Brazil — festivals, pubs, beaches — this can also contribute to a faster spread of the virus,” he said.
What does this mean for vaccines?
Some studies have suggested that this particular variant has the potential of causing reinfection, raising concern about the effectiveness of treatments and vaccines.
Shepperd said the “dreaded E484K mutation” decreases the ability for antibodies to bind to the spike protein of the virus. This means vaccines and therapeutics like monoclonal antibodies, which are laboratory-made proteins that mimic our immune system’s ability to fight off the coronavirus, will be less effective, he added.
Based on the evidence so far, the current vaccines do offer some protection against this variant and others, particularly from severe disease and death.
But, going forward, adjustments and minor modifications will have to be made to the vaccines with the possibility of a booster shot, both Pekosz and Shepperd said.
“These variants are signs that we do need to get ahead and plan for some sort of a booster strategy that may make the vaccines even more effective against some of these variants, particularly if they become the dominant strains of SARS-CoV-2 that are circulating,” Pekosz told Global News.
What measures are needed?
In light of the emergence of new variants, public health officials and experts have urged more caution and stressed the need to continue compliance with all pandemic response measures.
In Toronto, where the first case of the latest variant was found, a stay-at-home order is already in place.
Toronto Public Health advised all residents to be extremely mindful of time spent outside their household and said necessary trips should be kept as brief as possible.
“Those same things will be effective against this variant. We just need to make sure that we’re implementing them at a very high rate,” said Pekosz.
Starting this week, some provinces, including Ontario, Quebec and Alberta, have begun easing restrictions.
Bogoch said reopening should take place in a “very slow and measured manner.”
“If we don’t proceed with caution, there could be a spike in cases in the spring, and that might mean another lockdown.”View link »