A so-called “double mutant” variant of COVID-19 feared to be driving a record surge in new cases in India has now been found in Canada.
On Wednesday, British Columbia confirmed 39 cases of the B.1.617 variant – first detected in India – while Quebec reported it first known case of the new variant in the province.
In response to growing concerns, the Canadian government announced a 30-day ban on passenger flights from India and Pakistan Thursday.
While not officially designated as a variant of concern (VOC) by the Public Health Agency of Canada (PHAC), B.1.617 is being treated as a “variant of interest”. And federal health officials say they are closely monitoring it.
“We should be worried,” Donald Vinh, an infectious disease specialist and a medical microbiologist at the McGill University Health Centre, said.
“If a variant can spread into another country, that means it has some capacity for survival fitness and that usually means it’s as or more transmissible than the current strain,” he told Global News.
It is natural for all viruses to mutate, as their genetic material undergoes small changes during outbreaks.
Biologically, certain mutants give the spike protein — which is responsible for cell entry — a higher affinity for the receptor molecule on a healthy cell membrane, meaning the virus latches onto the human cells more effectively.
Here’s what we know so far about the new B.1.617 variant that has made its way into the country.
The B.1.617 variant was initially reported in the Indian state of Maharashtra late last year with two notable mutations – the E484Q and L452R.
The variant is being described as a “double mutant” due to a pair of mutations that the Indian Ministry of Health and Family Welfare says may confer “immune escape and increased infectivity.”
It has quickly become the dominant version of the coronavirus in the western state.
Scientists believe the variant is contributing to the recent uptick in infections in the country.
“We’re seeing a cluster of cases in various states and what we are seeing is more and more young people getting severely sick,” said Ananya Banerjee, assistant professor at the school of population and global health at McGill University.
The new strain has also been found in several other countries, including the United Kingdom, Australia, Germany, Belgium, Namibia, New Zealand, Singapore and the United States.
The E484Q mutation is similar to the E484K mutation found in the B.1.1.7 variant that was first detected in the U.K., the B.1.351 variant, which emerged in South Africa, and the P.1 variant behind Brazil’s deadly COVID-19 surge.
Experts say this mutation decreases the ability of antibodies to bind to the spike protein of the virus, making vaccines less effective.
The L452R mutation is also present in variants of concern in the U.S., including the fast-spreading B.1.427 and B.1.429 lineage in California.
According to the U.S Centers for Disease Control and Prevention, monoclonal antibody treatments, which use laboratory-made proteins that mimic our immune system’s ability to fight off the coronavirus, may be less effective against COVID-19 variants with the L452R or E484K substitution in the spike protein.
Vinh said having the L452R mutation will allow the B.1.617 variant to attach better to human cells, making it more transmissible.
The L452R mutation has also been associated with weaker neutralization of the virus by convalescent plasma from people who have been infected with the coronavirus, according to Sharon Peacock, professor of public health and microbiology at the University of Cambridge.
“Having two of these mutations, which have been seen in other variants around the world, are concerning because there’s a similarity in these mutations that confer increased transmissibility,” Maria Van Kerkhove, COVID-19 technical lead for the World Health Organization (WHO), said during a news conference last Friday.
“Some of these mutations also result in reduced neutralization, which may have an impact on our countermeasures, including the vaccines.”
The B.1.617 is considered as a “variant of interest” by the WHO as well as PHAC, meaning that it does not represent cause for stronger public health actions so far.
“At this point, the variants that have been identified in India are more variants of interest, which is not necessarily the same as variants of concern,” Howard Njoo, Canada’s deputy chief public health officer, said during a news conference on Thursday.
“We call it a variant of concern when it’s certainly shown to be more transmissible or more virulent, causing severe illness, hospitalization and death. It’s something being looked at very carefully, but at this point, we’re still analyzing the data.”
Higher transmissibility of this variant is not established as yet, India’s Health Ministry said in a statement on April 16.
Vinh said it’s not yet clear if the B.1.617 variant would necessarily be more transmissible than the other VOC that are circulating in the country.
“It just seems that it would be more contagious than the strain that we had before these variants.”
In an emailed statement to Global News, Anna Maddison, PHAC spokesperson, said: “At this time, there is insufficient evidence to determine if B.1.617 behaves significantly differently than the SARS-CoV-2 virus that has been predominant in Canada during the earlier phases of the pandemic, although evaluations are underway both in Canada and internationally.”
The person who tested positive for the B.1.617 variant in Quebec had been vaccinated against COVID-19, according to Quebec’s public health institute (INSPQ).
The presence of the E484Q mutation “threatens to decrease the effectiveness of the vaccine,” said Vinh.
But there is also a “glimmer of hope,” he added, from the experience of Israel, which has fully vaccinated around 81 per cent of citizens or residents over the age of 16.
“The impression is that Pfizer vaccine has efficacy against it, albeit a reduced efficacy,” an Israeli health official said on Tuesday, adding that the number of cases of the B.1.617 variant in Israel stood at eight.
Gigi Gronvall, senior scholar at the Johns Hopkins Center for Health Security, also allayed concerns about vaccine effectiveness.
“None of the variants that we have encountered so far seem to evade the vaccines that we have available,” she told Global News.
“Thankfully, the vaccines that we have stimulate quite a lot of antibodies to respond, so some changes in the virus are outmatched by the antibody levels that are produced.
“And also, we’re not just relying on antibodies. There’s other parts of the immune system, too.”
— With files from Reuters
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